It is known that metabolic processes constantly proceed with high intensity in a growing organism and various forms of metabolic energy received and expended in this process are converted into heat. A significant contribution to the formation of heat in the child's body (heat production - TP) is made by the high levels of metabolism and physical activity characteristic of children. The accumulation of heat in the body contributes to an increase in body temperature. However, in accordance with the physical laws of heat transfer, if the temperature of any body, including the human body, becomes higher than the temperature of the environment of its existence, heat from the surface of the body begins to dissipate into this environment (heat transfer - HT), which contributes to a decrease in body temperature. It is obvious that the temperature will be constant for a given body provided that the values ​​of TP and TO are equal. It is the maintenance of the equality of heat production and heat transfer under conditions of changes in the intensity of metabolism, motor activity of the body and (or) the temperature of the environment of existence that is one of the most important functions of the thermoregulation system.

Heat production per 1 kg of body weight increases over the 1st year of life up to 2.4 kcal per 1 hour. In children older than 2 years, heat production per unit body weight at rest gradually decreases, but at the same time their relative body surface area decreases, and by the age of 15-17, the indicators of heat transfer and the development of thermoregulation mechanisms approach the indicators characteristic of adults, when TP and TO become balanced and amount to about 1 kcal per 1 hour

The level of regulated body temperature is set in the body by the hypothalamic centers of thermoregulation. It is most likely that the preoptic area is directly related to determining the value of the regulated temperature (set point), the neurons of which are sensitive to a small change in local temperature and control all types of thermoregulatory reactions that occur when the temperature deviates from the temperature set for regulation. If the local temperature of the preoptic area deviates above the level set for regulation, for example, when the child’s motor activity increases, then thermoregulatory reactions will be initiated in the body, increasing heat transfer, contributing to a decrease in body temperature and returning the local temperature of the preoptic area to the value set for regulation (about 37 °C). If the local temperature of the preoptic area drops below the set value, for example, when cooling down while bathing, then thermoregulatory reactions will be initiated that reduce heat loss and, if necessary, increase heat production and contribute to an increase in body temperature and return the temperature of the preoptic area to a predetermined level. The preoptic region of the hypothalamus contains (about 30% of the total number) heat-sensitive neurons (TSN), which receive afferent signals through synaptic inputs from heat receptors (TR) in the skin and other tissues, and heat-insensitive neurons (TNN) (about 60%), which receive afferent signals from Cold receptors (CR).

HEAT TRANSFER MECHANISMS

The bulk of the heat is generated in the internal organs. Therefore, the internal flow of heat to be removed from the body must approach the skin. Heat transfer from internal organs is carried out due to heat conduction (less than 50% of heat is transferred in this way) and convection, i.e. heat and mass transfer. Blood, due to its high heat capacity, is a good conductor of heat.

The second heat flux is the flux directed from the skin to the environment. It is called the outward flow. When considering heat transfer mechanisms, this flow is usually meant.

Heat transfer to the environment is carried out using 4 main mechanisms:

1) evaporation;

2) heat conduction;

3) heat radiation;

4) convection.

HEAT PRODUCTION MECHANISMS

The source of heat in the body are exothermic reactions of oxidation of proteins, fats, carbohydrates, as well as ATP hydrolysis. During the hydrolysis of nutrients, part of the released energy is stored in ATP, and part is dissipated in the form of heat (primary heat). When using the energy accumulated in the AHF, part of the energy is used to perform useful work, part is dissipated in the form of heat (secondary heat). Thus, two heat flows - primary and secondary - are heat production. At a high temperature of the environment or when a person comes into contact with a hot body, the body can receive part of the heat from outside (exogenous heat).

If it is necessary to increase heat production (for example, under conditions of low ambient temperature), in addition to the possibility of obtaining heat from the outside, there are mechanisms in the body that increase heat production.

Classification of heat production mechanisms:

1. Contractile thermogenesis - heat production as a result of skeletal muscle contraction:

a) voluntary activity of the locomotor apparatus;

b) thermoregulatory tone;

c) cold muscle trembling, or involuntary rhythmic activity of skeletal muscles.

2. Non-shivering thermogenesis, or non-shivering thermogenesis (heat production as a result of activation of glycolysis, glycogenolysis and lipolysis):

a) in skeletal muscles (due to uncoupling of oxidative phosphorylation);

b) in the liver;

c) in brown fat;

d) due to the specific dynamic action of food.

contractile thermogenesis

With muscle contraction, ATP hydrolysis increases, and therefore the flow of secondary heat, which goes to warm the body, increases. Arbitrary muscle activity mainly occurs under the influence of the cerebral cortex. Human experience shows that in conditions of low environmental temperature, movement is necessary.

In children, unlike adults, the central nervous system is worse developed, so they are more susceptible to the influence of adverse environmental conditions. This leads to increased requirements for clothing in children. And the younger the child, the higher these requirements. And also in children, the processes of thermoregulation are not sufficiently developed. “More skin surface area with less body weight cause increased cooling of the body in cold, wet and windy weather and overheating in hot weather” . With the help of clothing around the body, an artificial under-clothing microclimate is created, which is significantly different from the climate of the external environment. Due to this, clothing significantly reduces body heat loss, helps to maintain a constant body temperature, facilitates the thermoregulatory function of the skin, and provides gas exchange processes through the skin. This is the main role of clothing. Protective clothing is important for children because:

In childhood, the mechanisms of thermoregulation are imperfect, hypothermia and overheating of the body can lead to health problems;

Children are distinguished by high motor activity, in which the level of heat production increases by 2-4 times;

The skin of children is tender and vulnerable;

Skin respiration has a greater share in the metabolic processes of the body than in adults.

Question

· Basic principle preschool nutrition is the maximum diversity of diets, which is achieved by using a sufficient range of products and various methods of cooking. Included in daily diet main product groups - meat, fish, milk, eggs, fruits, vegetables, sugar, bread, cereals, etc.

Exclusion from the diet of foods and dishes that can irritate the mucous membrane of the digestive system, as well as foods that could lead to poor health in children with chronic diseases9 without the stage of exacerbation) or compensated functional disorders of the gastrointestinal tract (sparing nutrition ).

· Taking into account the individual characteristics of children (including their intolerance to certain foods and dishes).

Ensuring sanitary and epidemiological safety of food, including compliance with all sanitary requirements for the state of the catering unit, food supplied, their transportation, storage, preparation and distribution of dishes.

Approximate kindergarten mode:

• from 7:00 to 8:00 - admission of children to a group, free activities;
• from 8:00 to 8:20 - breakfast;
• from 8:20 to 8:30 - free activity;
• from 8:30 to 9:00 - classes with children in groups;
• from 9:00 to 9:20 - preparation for a walk;
• from 9:20 to 11:20 - a walk in the fresh air;
• from 11:20 to 11:45 - return from a walk, free activities;
• from 11:45 to 12:20 - lunch time;
• from 12:20 to 12:45 - quiet games, preparation for daytime sleep;
• from 12:45 to 15:00 - quiet time;
• from 15:00 to 15:30 - rise, afternoon snack;
• from 15:30 to 15:45 - free activity;
• from 15:45 to 16:15 - classes with children in groups;
• from 16:15 to 16:30 - preparation for an evening walk;
• from 16:30 - a walk in the fresh air.

The time of free activity in the daily routine in kindergarten is provided for independent games. Also, children play with each other while walking outdoors. If the weather is bad outside, then instead of walking, the children spend time in a group. Summer mode in kindergarten somewhat different from other periods - at this time, children go on excursions, visit theaters, a zoo and other interesting places.

Meal time is the same in almost all kindergartens. Some changes are found in a private kindergarten - in addition to breakfast, lunch and afternoon tea, there is a second breakfast and dinner. The second breakfast, as a rule, consists of fruits, fortified foods and sweets. Children have dinner from 18:30 to 19:00.

Of great importance in the daily routine in kindergarten is not only the time of eating, but also the composition of the dishes. An approximate menu must necessarily include: dairy products, vegetables, fruits, meat and fish products, bread. Parents can ask in advance what the children are fed in a particular kindergarten.

During quiet time, all children rest. Even if the child does not want to sleep during the day, he just lies on the bed. As a rule, the time of daytime sleep is from 2 to 3 hours. Kindergarten lessons are of great importance for the full development of the child. The duration of classes, as a rule, does not exceed 30 minutes, so that the child does not have time to get tired. Basic activities in kindergarten:

• music lessons;
• classes for the development of speech;
• physical Culture;
• art;
• formation of primary mathematical skills.

All classes with children are held in groups depending on the age of the child. The time of classes in the senior and preparatory group is longer than in the younger and nursery.

Question.

hardening- this is an increase in the resistance of the human body to adverse environmental conditions. Hardening of children
necessary for the body to tolerate the impact
temperature changes, so that children are not afraid of hypothermia, drafts. At
hardened children, the incidence decreases and even if they get sick, then,
as a rule, the disease passes less painfully and without serious
consequences.

Children under 1 year old

The sun's rays are a very potent agent, ultraviolet is active
affects the immunological resistance of the organism. The younger
child, the higher the sensitivity to ultraviolet rays. That's why Sun exposure of a child less than a year old is not shown.

For hardening of children of the first year of life, only scattered and reflected rays are used. Conduct hardening
with children during wakefulness, it is necessary under a canopy or in the shade
trees. It should be remembered that you can undress to the goal only after 25
- 30 minutes after sleep, a Panama hat should be put on the baby's head with
visor. Immediately after sleep, in the absence of wind and air temperature
+22 +26 baby needs to wear shorts and shirt made of light fabric. Through
30 minutes the baby is exposed for 3 minutes (gradually after 1-2 days the time
increased by 2 minutes and adjusted to 10 minutes). In a warm windless
weather, such sunbathing can be carried out during every walk on
fresh air. It is desirable that the baby was able to move,
played with toys, and very young children need to turn themselves
on different sides and spread on the tummy.

Children from 1 to 3 years old

Children from one to three years of age are carried out with caution sunbathing,
children are taken out into direct sunlight only after
For several days the walk was carried out in chiaroscuro. In scattered
solar rays are relatively few infrared rays and quite a lot
ultraviolet, which is the prevention of overheating of the body
child. Overheating is very dangerous for children with high
neuro-reflex excitability. Therefore, it is better to choose clothes
light colors, it will protect the child from overheating and excessive
irradiation.

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The body of a newborn, accustomed for 9 months to a temperature of 38 ° C in the mother's womb, faced with new conditions, where the temperature is 10-15 ° lower, does not yet have adaptation mechanisms. This can lead to hypothermia of the body and the development of diseases against this background. On the other hand, cooling an infant is sometimes medically necessary.

Symptoms of hypothermia in a newborn

Parents of a newborn child should carefully monitor his condition, avoiding hypothermia, and at the same time train the body of the baby, develop the mechanism of thermoregulation in it. This should be done very gently and gradually, avoiding sudden changes in the temperature of the environment of the newborn.

And yet, it often happens that the baby gets cold.. Since he is not yet able to report this, parents need to be very careful and know how the hypothermia of the baby manifests itself.

Signs of hypothermia in a newborn:

• Change in skin color: it acquires a bluish tint, may have a spotted "marble" appearance, cyanosis is characteristic above the upper lip;
• The skin is cool to the touch in natural folds (armpits, in the groin, in the elbow and popliteal fossae);
• hiccups;
• Trembling in the body;
• Dry cough;
• Decreased body temperature to 35-34°C.

Important: a cold nose, fingers and toes are not symptoms of hypothermia, but are associated with the peculiarities of blood circulation.

Treatment of hypothermia of the newborn

What should I do if my baby shows signs of hypothermia? Tactics depend on how long the newborn was in conditions of low temperature, but his condition is more important.

If the newborn is active, mobile, reacts vividly to communication with him, if the temperature is not lower than 35.5 ° C, he just needs to be warmed and fed.

The best option for natural warming is to attach the baby to the mother's body, wrap in a warm blanket, breastfeed or, if formula-fed, warm (37-39°C) formula. If these measures are not enough, you need to make the child a warm bath.

It is important to observe the temperature regime: at first, the water should be 32 ° C, then gradually increase the temperature to 37 ° C, adding hot water, after removing the baby from the bath.

In the water, you need to do a light massage of the child’s body by the type of stroking and weak kneading between 2 fingers, make blurry movements with the arms, legs, turn him over on his side, stomach, back again.

If the baby relaxes, begins to actively move in the bathroom, the skin acquires a normal pink color - the warming effect is achieved. The duration of the bath is 10-15 minutes.

After the bath, wipe the newborn dry with a soft towel, put on cotton and warm underwear, warm socks, a cap, cover with a blanket. After half an hour, you need to measure the baby's body temperature.

If the baby has trembling, cyanosis of the skin, lethargy, refusal to eat, cough, runny nose, body temperature is reduced to 35 ° C and below, you should immediately consult a doctor.

It is impossible to make a bath, and even more so to put such a newborn to bed. Sleep during severe hypothermia is dangerous, it can mask the developing complications.

Consequences and complications

Hypothermia of a newborn is very dangerous. It leads to impaired blood circulation and, as a result, hypoxia (oxygen starvation) of all organs and tissues. The brain suffers the most. This explains the excessive calmness of the child when he freezes.

Hypothermia of a newborn in the absence of timely measures to warm the baby's body can lead to a number of inflammatory complications:

• Upper respiratory tract (rhinitis, laryngitis, tracheitis);
• tonsils (tonsillitis);
• Paranasal sinuses (sinusitis);
• Bronchov (bronchitis);
• Lungs (pneumonia);
• Kidneys (glomerulonephritis, pyelonephritis).

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More severe consequences are frostbite, cerebral coma and death..

Frostbite of the extremities in this case is not associated with being in the cold, but with a prolonged circulatory disorder due to vasospasm and tissue hypoxia. This is the same reason for pathological changes in the brain.

Prevention of hypothermia in newborns

Since ancient times, maternal warmth has been the most important warming factor for babies. It has been established that if a newborn does not contact the mother's body for 20 minutes or more before 2-3 weeks, its temperature begins to decrease. This should be remembered, especially for young mothers, despite modern views, raising children in a Spartan spirit and “not accustoming to hands”, this is a delusion.

Important: you can not unnecessarily wrap the newborn. Overheating leads to sweating, and wet underwear will certainly lead to hypothermia, a cold. A sweaty baby should be wiped dry with a towel and changed.

The newborn needs to be helped to adapt to new, more severe living conditions.. This process inevitably occurs when changing clothes, washing, daily bathing the baby. You need to keep the child naked for 2-3 minutes 2 times a day, gradually increasing the time to 10 minutes.

From 2 weeks of age, walks in the fresh air begin. In this case, the child should be warmly dressed, protected from the wind. It is useful to gradually increase the duration of bathing, to create conditions for the baby to swim in the bathroom.

You should also not use extreme methods - a steam room, cold water, rubbing with snow, and the like. All questions regarding the hardening of the child must be agreed with the pediatrician.

Indications for the use of artificial hypothermia in infants

Hypothermia or hypothermia of the body of a newborn can also do a good job when it is carried out for medical reasons.

• With asphyxia of the newborn;
• With encephalopathy;
• With metabolic acidosis;
• With convulsive syndrome;
• If the Apgar score is less than 5 points.

All of these conditions are accompanied by oxygen starvation, which eventually leads to failure of organs.

According to statistics, every year in the world 1 million children are born with hypoxia of various origins, and, as a result, 20% of them develop cerebral palsy (ICP).

The role of artificial hypothermia in newborns is to reduce the overall metabolism and, accordingly, the need for oxygen in the cells of the body. Under conditions of hypoxia, cooling prevents the death of cells, in particular, the brain, and preserves their viability.

Therapeutic hypothermia of newborns

A newborn who is indicated for artificial cooling is placed immediately in the intensive care unit, an artificial lung ventilation (ALV) device is connected, a catheter is installed in the veins for constant maintenance drug therapy.

Sensors of basic functions are connected, including body temperature, all information from which is constantly visible on the monitor (pulse, pressure, cardiography, encephalography, body thermography).

After all the necessary studies and emergency drug therapy, the child is connected to an artificial hypothermia apparatus no later than 6 hours from the moment of birth. The newborn hypothermia device has 2 sensors: one is applied to the skin, the other is inserted into the rectum. Cooling of the body lasts for an hour to a temperature of 34-33°C.

The duration of the procedure is 3.5 days (84 hours), it is carried out in 2 stages:

Craniocerebral hypothermia of the infant

Cooling the head of a newborn is a very important life-saving procedure for infants born with encephalopathy. It develops as a result of asphyxia and oxygen starvation of the brain during entanglement with the umbilical cord, difficult labor with compression of the head, and other causes.

As a result of oxygen starvation, the newborn develops cerebral edema, metabolic processes in the nervous tissue are disturbed and its damage occurs. These changes are usually irreversible. Most often, the outcome is various kinds of paralysis and other disorders of the central nervous system.

Craniocerebral hypothermia of newborns with asphyxia makes it possible to reduce the activity of vital processes in the brain, thereby reducing its need for oxygen by 6–7% for each lowered degree of temperature. As a result, hypoxia is eliminated.

Cooling is performed from above - from the bones of the skull, meninges and cortex to its deeper structures. At the same time, the flow of blood to the brain, going through the arteries from below, remains normal. Most of the brain neurons, even with severe encephalopathy, are preserved.

Thermoregulation is a complex process that reflects the manifestations of the subtle interaction of the human body with the external environment. Various parts of the nervous and humoral systems take part in its implementation.

Physiological mechanisms that determine the constancy of body temperature, i.e., carry out thermoregulation, are divided into chemical and physical. Chemical thermoregulation provides an increase in heat production when the body cools down (lower ambient temperature, increased heat consumption). The main source of heat production in humans is the skeletal muscles (contraction of muscle fibers or an increase in their tone). The second important source of heat production is the liver, along with other digestive organs. Physical thermoregulation carries out the processes of heat transfer from the body through convection, radiation and evaporation, while the main role is played by the blood vessels of the skin. The division of thermoregulation into chemical and physical is to a certain extent conditional, since they are closely related and mutually dependent.

It is believed that heat production and heat retention in the body are mainly regulated by the posterior nuclei of the hypothalamus, and heat loss and a decrease in heat production are carried out with the help of the regulatory influence of the predominantly anterior nuclei of the hypothalamus. Removal of the hypothalamus results in the loss of the ability to regulate body temperature, making the animal poikilothermic.

An important role in thermoregulation is also played by the endocrine glands, especially the thyroid gland, adrenal glands and pituitary gland, whose hormonal activity is regulated by the nervous system. The role of these glands is reduced mainly to the influence of heat production. Their impact on heat transfer is much less.

Thermoregulation in newborns has a number of features associated with the morphological and functional immaturity of the central and peripheral mechanisms. In premature babies, the immaturity of the cerebral cortex is more pronounced than in full-term newborns. One of the reasons for the imperfection of thermoregulation in prematurely born children, apparently, is the deep functional immaturity of the interstitial brain. In the fetus, all nuclei of the hypothalamus are formed by the time of birth and are similar in topography, structure and shape to the nuclei of an adult. However, the structural differentiation of the hypothalamic formations has not yet been smoked and is carried out much later.

Numerous studies of domestic and foreign authors have shown that the mechanism of chemical thermoregulation in newborns is well developed. Already in the first hours after birth, even in premature babies who have undergone cooling, heat production increases. The improvement of chemical thermoregulation in full-term newborns, according to O. V. Bepevskaya, occurs by the end of the 1st month, and in premature babies - at the 3-4th month of life. The inferiority of thermoregulation in the period of the newborn is associated with the underdevelopment of the physical link of thermoregulation.

An interesting question is about the source of heat production in full-term and premature newborns. As is known, children of this age period do not have a shivering reaction when the ambient temperature drops, i.e. they are capable of generating heat production without switching on muscle activity. The processes of pesrative inhibition are carried out by activating the sympathetic nervous system - norepinephrine is a specific mediator.

Recent studies have shown that brown adipose tissue is a powerful source of heat production. Brown adipose tissue, which develops from mesenchymal cells, in children is located in the interscapular and axillary regions, in the region of the thyroid and goiter glands, pericardium, around the esophagus, kidneys and adrenal glands, trachea, in the mesentery of the small intestines, in the groin and along the large vessels. It is believed that under cold exposure in newborns, fatty acids are oxidized in brown adipose tissue, as a result of which a large amount of heat is released, tissue and blood are heated in nearby vessels.

Our observations of rectal and skin temperature in newborns subjected to cooling, carried out at the Institute of Pediatrics of the USSR Academy of Medical Sciences together with I. A. Kornienko, V. N. Bogachev, Yu. M. Pavlov and V. N. Tsukanov, showed that the average temperature ; the interscapular region is always higher; than the average skin temperature of the rest of the body. Our results are consistent with the opinion of Silverman, who also links the rise in temperature in the interscapular region in children with an increase in heat production in brown adipose tissue. Examination of children using a thermal imager, which allows measuring the intensity of infrared radiation of tissues, confirmed the data obtained using conventional research methods. In healthy full-term and premature newborns, the response to cooling at a temperature of 21-23°, despite various individual characteristics, is always associated with the activation of heat production in brown adipose tissue.

The formation of heat as a result of an increase in the intensity of metabolism under the influence of cooling occurs, of course, not only in the cells of brown adipose tissue. These processes also occur in other tissues, but the role of heat generation in brown adipose tissue during the neonatal period is very significant.

Before the birth of a child, the "training" of thermoreceptors and, in general, the entire system of heat production is reduced to a minimum due to the fairly high stability of the body temperature of a pregnant woman. The transition of a child to extrauterine existence is accompanied, first of all, by a powerful load on thermoreception, since the temperature of the air surrounding him is 10-14 ° lower than the temperature at which the fetus develops.

In a newly born child, the temperature measured in the rectum ranges from 37.7 to 38.2 °. According to A. V. Tokareva, in the first hours of life, the body temperature of a newborn corresponds to the temperature of the mother's body. At the age of 3 hours of life, the temperature drops to 35.2 °, and then rises again. In the first 5 days of life, body temperature undergoes significant fluctuations, from the 6th day it is set at a relatively constant level (36.2 °), although its complete stabilization occurs only at the beginning of the 2nd month of life.

In premature babies, according to Yu. A. Mucheidze, who conducted his observations in the clinic for premature babies of the Institute of Pediatrics of the USSR Academy of Medical Sciences, the level of rectal temperature, despite special warming measures, in the first 10 days of life is at rather low figures (35.3 °). This means that the function of heat generation in a physiologically immature organism, such as a premature baby, is not able to provide the level of thermal energy at which normal life activity is carried out. Marked sharp fluctuations in body temperature during the day, expressed the more, the greater the degree of prematurity of the child. In children at the age of 1 month, the temperature acquires relative stability (its average level is 37.2 °).

The skin with its vascular system plays an important role in maintaining body temperature. For full-term children, a high level of skin temperature is characteristic compared to an adult, which is explained by a high level of metabolism, the prevalence of vasodilating reactions, and structural features of the blood supply to the skin. The temperature of the skin of the central parts of the body in full-term newborns is higher than in the peripheral areas. In the first days of life, the skin temperature on the left side of the body is higher than on the right, according to 11. Koeva-Slavkova, by 0.17 °. A. V. Tokareva also noted the asymmetry of skin temperature in children throughout the entire neonatal period. According to her, the highest level of skin temperature on the first day of life was noted in the hypochondrium (35.2°), on the skin of the chest (34.9°), hands (34.5°), and the lowest - on the fingers stop (31.7°).

Premature babies, according to 10. A. Muchaidze, are characterized by higher skin temperatures than full-term babies and adults. The more premature the baby, the higher the skin temperature. Thus, the insufficiency of the function of heat production in preterm infants is exacerbated by the dissipation of heat through skin radiation. In premature babies, the temperature of the skin of the proximal extremities did not always exceed the temperature of the skin of the distal parts, sometimes it was equal to it or was lower. The maximum difference in skin temperature in different parts of the body in premature infants during the first 10 days of life was 2.5°, at the age of 1 month - 1.4°.

A decrease in skin temperature in the absence of changes in rectal temperature begins only at the 3rd month of life, which can be considered an external manifestation of the onset of vascular regulation of skin radiation in these children.

The study of the Shcherbak reflex in premature babies, conducted by Yu. A. Muchaidze, made it possible to obtain a more in-depth characterization of the level of maturity of thermoregulation mechanisms. When a child's hand was immersed for 15 minutes in a bath with warm water, instead of the expected rise in body temperature, which occurs in adults, the rectal temperature in premature babies during the first 10 days of life fell by 0.4-1.2°. An increase in temperature to the initial level was not observed within 4-5 hours. In children weighing more than 1500 g at birth, fluctuations in skin temperature were similar to rectal ones. In children with very low birth weight, skin temperature gave more pronounced shifts on the arm opposite to the application of thermal stimulation. It can be assumed that the described type of reactions in children of the first 10 days of life to a heat test indicates an inability to urgently stabilize the temperature of the internal environment of the body. Only from the end of the 2nd - the beginning of the 3rd month of life does some normalization of the response data occur during the Shcherbak test.

The inconsistency in the system of mechanisms that ensure heat production and heat transfer indicates that by 6-7 months of intrauterine development, the functional system of thermoregulation has not yet formed as a unit of physiological integration.

The establishment of the daily periodicity of body temperature may indicate the time of improvement of the function of thermoregulation by higher central mechanisms. There is no clear information about this process in the literature. N. A. Arkhangelskaya believes that already from the first days after birth, children have a daily periodicity of body temperature, which is the opposite in value to that which the mother has. N. Koeva-Slavkova observed a daytime increase in temperature and a nighttime decrease in it, that is, a daily period in full-term newborns already on the 4th-5th day of life.

V. N. Bogachev, who studied the function of thermoregulation in newborns and infants, noted the appearance of a daily rhythm of body temperature in full-term children at the age of 1 month. However, he believes that the body temperature periodicity that has appeared is still largely different from that observed in adults. The daily rhythm of heart rate and respiration in these children begin to correlate with body temperature from the beginning of the 2nd month of life.

Hellbrugge, who has extensively studied the formation of circadian rhythms in newborns, believes that the daily periodicity of body temperature is set at 2-3 weeks of life.

The temperature analyzer in premature babies develops more slowly and matures structurally and functionally at a later date. According to Yu. A. Muchaidze, in premature babies of the first 3 months of life, there is no daily period of body temperature, and only by the end of the 3rd - at the beginning of the 4th month in some children weighing 2000 g at birth, there is a tendency to daily increase temperature and some decrease in it at night. This, in the author's opinion, may indicate the inclusion of the cortical part of the temperature analyzer.

Due to the morphological and functional immaturity of a premature baby, their reserves of heat generation are extremely limited. Even in inflammatory diseases, in which fever is specific, hyperthermia in premature babies, as a rule, does not occur.

Studies by Yu. A. Muchaidze showed that nursing very premature babies in closed-type incubators (that is, under conditions that protect their body from excessive energy losses) accelerated the maturation of the thermoregulatory function.

Since in early ontogenesis the improvement of chemical thermoregulation precedes physical one, in connection with this, overheating easily occurs in newborns. The reason for this lies not only in the insufficient regulation of heat release by convection and radiation, but also in the characteristics of perspiration. The sweat glands in newborns are still underdeveloped and their sweat secretion is limited. The beginning of sweating was registered in some children on the 4th day; this reaction was most clearly detected in children at the end of the 3rd - beginning of the 4th week. There was no correlation between the child's weight and the onset of sweating. Children of the first 7-10 days of life do not tolerate cooling well. A. V. Tokareva showed that a newborn child left without clothes at a temperature of 26 ° and even 28 ° has a drop in skin temperature, anxiety, hiccups, acrocyanosis, and urination appear.

The imperfection of thermoregulation in newborns, which in general terms consists in reduced heat production and increased heat transfer, should be taken into account when organizing their temperature regime. This is directly related to full-term newborns, in whom in the first 7-10 days of life there is an improvement in chemical regulation, metabolism and relative stabilization of body temperature. The daily heat production, which, according to V.P. Spirina, in full-term newborns on the first day of life is 45 cal, increases in subsequent days and on the 7th day is 58 cal. The optimal temperature regime for full-term and premature newborns should be considered the one in which the child maintains a constant body temperature with the least thermoregulation stress.

FEATURES OF THERMOREGULATION IN CHILDREN. It is known that metabolic processes constantly proceed with high intensity in a growing organism and various forms of metabolic energy received and expended in this process are converted into heat. A significant contribution to the formation of heat in the child's body (heat production - TP) is made by the high levels of metabolism and physical activity characteristic of children. The accumulation of heat in the body contributes to an increase in body temperature. However, in accordance with the physical laws of heat transfer, if the temperature of any body, including the human body, becomes higher than the temperature of the environment of its existence, heat from the surface of the body begins to dissipate into this environment (heat transfer - HT), which contributes to a decrease in body temperature. It is obvious that the temperature will be constant for a given body provided that the values ​​of TP and TO are equal. It is the maintenance of the equality of heat production and heat transfer under conditions of changes in the intensity of metabolism, motor activity of the body and (or) the temperature of the environment of existence that is one of the most important functions of the thermoregulation system.

The value of body temperature, when the values ​​of TP and TO are equal, could be set at various arbitrary levels, but due to the function of the central - hypothalamic - centers of thermoregulation, this temperature value is quite definite ("37 ° C). This is called the thermoregulation set point. Thus, the formation by the central neuronal structures of the hypothalamus of a certain value of temperature regulated in a given organism is the second most important function of the thermoregulation system. If both of these functions are performed successfully, then the thermoregulation system provides a solution to its main task - it maintains the temperature of the brain and other tissues of the "core" of the body at a relatively constant level. This temperature is maintained at a minimum tension of thermoregulation mechanisms under conditions of a slight fluctuation in the temperature of the external air or within the so-called thermoneutral, or thermally indifferent, zone - for a naked adult in the range of 28-30 "C, for a newborn - 32-34 °C, and for lightly dressed children aged 1 month - 22-25 "C, 6 months - 19-23" C, 1 year - 17-21 ° C.

Heat production. The total heat production in the body consists of the primary heat released in the course of constantly occurring metabolic reactions in all organs and tissues, and the secondary heat generated when the energy of macroergic compounds is spent on the performance of muscle work and other functions. TP in the child's body depends on the magnitude of the basal metabolism, the "specific dynamic action" of the food taken, muscle activity and changes in the intensity of metabolism associated with a change

ambient temperature (facultative thermogenesis). Metabolic processes are carried out with unequal intensity in different organs and tissues, and therefore the contribution of individual organs and tissues to the total TP of the body is unequal. The greatest amount of heat is generated in the organs and tissues of the "core" of the body: the liver, kidneys, brain, working muscles (with tonic tension and contraction - contractile thermogenesis).

The amount of heat necessary to maintain body temperature is produced in a full-term baby immediately after birth. TP in a newborn is about 1.5 kcal per 1 kg of body weight for 1 hour. An increase in heat production after birth is provided by the activation of oxidation of free fatty acids in the mitochondria of fat cells, the level of which increases with an increase in the tone of the sympathetic nervous system, stimulation of p-adrenergic receptors with catecholamines and activation protein kinase A, which increases the activity of the enzyme lipase of brown adipose tissue (BAT). A more powerful and prolonged increase in heat production is achieved by the action of thyroid hormones on mitochondrial oxidation processes in fat cells. At the same time, the increase in TP is achieved by accelerating the basic metabolic processes (basal metabolism) and by activating the mechanisms of facultative thermogenesis, which provide an increase in heat generation under conditions of a decrease in the temperature of the environment. Both the intensity of basal metabolism in the body and the thermogenic function of brown adipose tissue depend on the level of thyroid hormones. Oxidation of fatty acids in brown adipose tissue, the mass of which in a full-term newborn is about 2% of body weight (25-35 g), is carried out without significant synthesis of macroergs and with the maximum possible formation of primary heat. The white adipose tissue of the newborn is also capable of direct heat generation, but to a much lesser extent. Through the mechanism of non-shivering thermogenesis, the level of heat production can be increased several times compared to the level of basal metabolism. At the same time, even in full-term children, the reserves of heat-producing adipose tissue, including brown, rapidly decrease, reaching a minimum by the 3-4th week after birth. The higher the serum level of T4 and T3, the higher the level of gene expression in the nuclei of brown adipose tissue adipocytes responsible for the synthesis of the thermogenin protein, which uncouples the processes of respiration and phosphorylation, reduces ATP synthesis in mitochondria and increases heat generation. T3 affects thermogenesis in brown adipose tissue by modulating the activity of the enzyme deiodinase D2, which determines the rate of formation of other active forms of thyroid hormones from T4 and their metabolic breakdown in tissues. The maximum stimulation of thermogenin gene expression is achieved by the simultaneous action of thyroid hormones and catecholamines. By the time of birth, this action reaches its greatest intensity and provides conditions for the maximum thermogenic activity of brown adipose tissue in the early postnatal period.

With a significant degree of prematurity, when newborns have hypothyroidism of varying severity, and the mass of brown adipose tissue is less than 1% of body weight, heat production is reduced. This can contribute to the development of hypothermia if conditions are not created to limit heat loss.

Contractile thermogenesis is also an important mechanism for increasing TP in a newborn, who already from the first hours of life has an increase in muscle tone and motor activity, which sharply increase with Chloride exposure to the skin. The role of contractile thermogenesis in increasing heat production increases as the age of the child increases and the mass of brown adipose tissue decreases. This is facilitated by an increase in muscle mass in children, the development of mechanisms of thermoregulatory muscle tone and cold shivering. The contribution of contractile thermogenesis to TP may change in a number of neurological and muscular diseases, as well as in the development of hypoxia caused by diseases of the circulatory and respiratory organs.

Heat production per 1 kg of body weight increases over the 1st year of life up to 2.4 kcal per 1 hour. In children older than 2 years, heat production per unit body weight at rest gradually decreases, but at the same time their relative body surface area decreases, and By the age of 15-17, the indicators of heat transfer and the development of thermoregulation mechanisms approach those typical for adults, when TP and TO become balanced and amount to about 1 kcal per 1 hour.

The level of heat production is controlled by effector neurons of the posterior hypothalamus through somatic and sympathetic nerve fibers, as well as by a number of hormones and biologically active substances (norepinephrine, adrenaline, thyroxine, triiodothyronine, etc.).

Heat dissipation. The following mechanisms of heat transfer by the body to the environment are distinguished: radiation, heat conduction, convection, evaporation of moisture. TO by the first three methods can be carried out only under the condition that the temperature of the body surface is higher than the temperature of the environment of existence. TE due to the evaporation of moisture can be carried out both in the presence of a positive difference in the temperatures of the surface of the body and the environment, and in conditions of a higher temperature of the external environment. TE by evaporation stops at 100% saturation of the external

air environment with water vapor or in water. All of the above methods of heat transfer obey physical laws.

Due to the occurrence of physiological reactions of the body to the effects of heat, cold or a significant change in heat production, it is possible to influence the value of the body surface temperature, and thereby the value of the temperature gradient between the body surface and the environment and the value of TO. These reactions are vascular reactions - narrowing or expansion of superficial vessels of the skin. If vasodilatation is not enough to increase heat transfer (under conditions of high external temperature), then sweating is stimulated, which creates additional opportunities for enhancing the TO by evaporating more moisture from the skin surface and lowering body temperature. In conditions when, under the action of cold, vasoconstriction is insufficient to reduce heat loss and prevent cooling of the body, physiological reactions of increasing TP are stimulated (contractile and non-contractile thermogenesis). Thus, TO by any of the methods is by its nature a passive physical process, and the physiological thermoregulatory reactions of vessels or perspiration only contribute to changing the conditions for dissipating more or less heat into the environment and achieving a balance between the values ​​of TP and TO.

Radiation is a method of transferring heat from the surface of the body to the environment in the form of electromagnetic waves in the infrared range. The amount of heat dissipated by radiation into the environment is proportional to the surface area of ​​the skin of those parts of the body that are in contact with air. At an air temperature of 30-34 "C and a relative humidity of 40-60%, the surface of the body of a naked child of the 1st month of life dissipates about 40% of the total heat emitted by radiation. TO by radiation increases with a decrease in ambient temperature and (or) an increase in skin temperature and decreases with an increase in the temperature of the external environment and (or) a decrease in the temperature of the skin.If the ambient temperature exceeds the average temperature of the skin, the human body, by absorbing infrared rays emitted by objects, warms up.If the temperature of the surface of the skin and the environment is equalized, the heat transfer stops.

The skin of newborns and young children is well vascularized, and due to the intensive flow of heated blood to the body surface from the internal organs, the temperature of the skin in children is higher than in adults. In addition to a higher temperature gradient between the surface of the body and the external environment, children have a number of other factors that cause intense TO. This is 2 times the body surface area per 1 kg of body weight, the small thickness of the skin and its low thermal insulation properties, especially when the subcutaneous fat layer is insufficient.

The maturation of the mechanisms of regulation of TO in a child lags behind the development of the mechanisms of regulation of heat production and is actually completed only by the age of 7-8 years. Earlier (by 6 months–1 year), the mechanisms of TO regulation mature through the reactions of superficial vessels, the nature of which can be judged at room temperature by changes in the temperature difference on the chest and limbs in a naked child.

An increase in the functional activity of the sweat glands and the regulation of sweating develop in children at a later date. The delay in the development of mechanisms that control heat transfer, in comparison with the development of mechanisms for regulating heat production, determines that if elementary precautions are not observed or if some diseases develop, overheating of children in the first months and years of life is more likely than their hypothermia.

The states of overheating or hypothermia of the child's body are especially likely when the body comes into contact with the aquatic environment (baths) or with other physical bodies (cold operating table and other conditions), when heat is dissipated through heat conduction. In this case, the HT intensity also depends on the temperature gradient of the contacting bodies, the area of ​​the contacting surfaces, the thermal contact time, and the thermal conductivity of the contacting body. Dry air, adipose tissue are heat insulators, and wet clothes, moist air saturated with water vapor and water, on the contrary, are characterized by high thermal conductivity.

High rates of dissipation, heat and overheating or hypothermia of the child's body are achieved when they give off heat to convection currents of air or water. Naked children of the 1st month of life at an air temperature of 30-34 ° C give off about 36% of heat to convection air currents.

The high intensity of TO in children is also facilitated by heat dissipation through the evaporation of moisture from the surface of the body and from the mucous membrane of the respiratory tract. In children, a significant amount of moisture perspires through a thin layer of the epidermis of the skin and constantly evaporates from the surface of the skin (imperceptible perspiration). The total amount of heat dissipated by the naked body of a child due to the evaporation of water is under normal conditions about 24%. When the external temperature exceeds the average value of the skin temperature, the body cannot give off heat to the external environment by radiation, convection and heat conduction. The body in these conditions begins to absorb heat from the outside, and the only way to prevent

its overheating becomes an increase in heat dissipation through sweating and evaporation of moisture from the surface of the body. Sweating begins in newborns with an increase in rectal temperature to 37.2 ° C (sweating threshold) and reaches its highest intensity after 35-40 minutes. In newborns, the density of sweat glands is higher than in adults, but their functionality is lower. The sweat glands of a child can produce up to 57 ml of sweat per 1 kg of body weight per day, and an adult - up to 500 ml. With age, the temperature threshold for sweating decreases and the functional activity of the sweat glands increases.

Moisture evaporation is possible as long as the ambient air humidity remains below 100%. With intense sweating, high humidity and low air velocity, when sweat droplets, not having time to evaporate, merge and drain from the surface of the body, heat transfer by evaporation becomes less effective and overheating of the body may occur.

Blood circulation plays a decisive role in the removal of heat from the internal organs and tissues that produce it in large quantities, and in preventing their overheating. Blood has a high heat capacity, and by increasing or weakening the blood flow directed to the surface tissues, heat is transferred to the surface of the body, it is warmed or cooled, and conditions are created for greater or lesser heat transfer to the environment.

The level of regulated body temperature is set in the body by the hypothalamic centers of thermoregulation. It is most likely that the preoptic area is directly related to determining the value of the regulated temperature (set point), the neurons of which are sensitive to a small change in local temperature and control all types of thermoregulatory reactions that occur when the temperature deviates from the temperature set for regulation. If the local temperature of the preoptic area deviates above the level set for regulation, for example, when the child’s motor activity increases, then thermoregulatory reactions will be initiated in the body, increasing heat transfer, contributing to a decrease in body temperature and returning the local temperature of the preoptic area to the value set for regulation (about 37 °C). If the local temperature of the preoptic area drops below the set value, for example, when cooling down while bathing, then thermoregulatory reactions will be initiated that reduce heat loss and, if necessary, increase heat production and contribute to an increase in body temperature and return the temperature of the preoptic area to a predetermined level. The preoptic region of the hypothalamus contains (about 30% of the total number) heat-sensitive neurons (TSN), which receive afferent signals through synaptic inputs from heat receptors (TR) of the skin and other tissues, and heat-insensitive neurons (TNN) (about 60%), which receive afferent signals from Cold receptors (CR).

Both in full-term and premature babies, skin receptors are well developed. The most sensitive zone of thermoreception is the skin of the face, innervated by the trigeminal nerve. About 10% of neurons are classified as cold-sensitive (CSN), since their activity increases with decreasing temperature. Since the neurons of the preoptic region are sensitive both to changes in local temperature and to signals from thermoreceptors about the nature of temperature changes in the periphery, they integrate both of these types of information and, depending on the value of the integral body temperature, send one or another signal to effector neurons, triggering thermoregulatory reactions.

Thus, heat-sensitive neurons under conditions of thermally indifferent ambient temperature and a slight (>0.011 °C) increase in the local temperature of the preoptic region above 37 °C activate effector neurons through excitatory synapses located in the posterior hypothalamus and triggering thermoregulatory reactions of heat transfer. At the same time, heat-sensitive neurons can inhibit the activity of effector neurons that control the level of heat production in the body through inhibitory synapses. However, under conditions of high ambient temperature, when STNs receive an activating afferent inflow from thermal receptors, they can trigger a heat transfer reaction through the activation of effector neurons, when there has not yet been an increase in local temperature in the preoptic region.

Under the action of cold, the afferent inflow from CR goes to thermoinsensitive neurons, which, after their activation, can have an excitatory effect on effector neurons that trigger reactions to increase heat production, and at the same time can inhibit the activity of effector neurons that control the level of heat transfer, while reducing heat dissipation.

Effector neurons, whose activity depends on the receipt of signals from both SN and TN of the preoptic region, have both excitatory and inhibitory synaptic inputs. Obviously, effector neurons will be activated if the input of signals through excitatory synapses prevails, and their activity will decrease if the input of signals through inhibitory synapses prevails. It is assumed that the value of the regulated body temperature will be set at the temperature value (set point), at which the signal flows from the TNV will be equivalent to the signal flows of the opposite sign from the TNV. Under normal conditions, in a healthy person, the temperature value, or the set point value, is the one at which the equivalence of the flow of excitatory and inhibitory signal flows to effector neurons from STN and TNN is achieved, and is about 37 °C. At this temperature value, the activity of effector neurons is close to zero, but with a change in the local temperature of the preoptic region or a change in the afferent inflow from peripheral thermoreceptors, there is such a change in the activity of effector neurons that is necessary to trigger thermoregulatory reactions and maintain body temperature at a given level for a given organism. .

The maturation of the central hypothalamic mechanisms of thermoregulation in children can be judged by the establishment of the correct daily rhythm of body temperature, which occurs by 1.5-2 months of age. Hypoxia, intracranial trauma, infections that affect the central nervous system, as well as its anomalies, can cause dysfunction of the central apparatus of thermoregulation.

Body temperature. The fetus, located in the womb at a relatively constant temperature of her body, does not need its own thermoregulation. The heat generated by the body of the fetus is transmitted through the placenta to the mother's blood, and the temperature of the blood flowing from the fetus to the placenta is 0.3-0.5 ° C higher than that of the blood flowing to the fetus. The value of fetal TP before delivery is about 10-15% of the value of maternal TP.

Body temperature (rectal) in a healthy newborn is 37.7-38.2 ° C, which is 0.1-0.6 "C higher than the mother's body temperature. In children born prematurely, born in asphyxia or severely injured at birth, there is a significant decrease in body temperature, which can persist for several days. Decrease in temperature to 35 "C and below, later return to normal

mu level and significant subsequent fluctuations in body temperature usually indicate a lack of thermoregulation mechanisms.

Within the next few hours after birth, the body temperature in healthy newborns decreases by 1.5-2 °C. The degree of decrease in body temperature is affected by the weight of the child, the size of his body, the amount of original cheesy lubricant, the conditions for caring for the newborn. In healthy children, body temperature soon begins to rise and after 12-24 hours reaches 36-37 ° C. The axillary temperature at birth is about 37.2 °C, after 2-3 hours it drops to 35.7 °C, by the 4-5th hour it gradually rises to 36.5 °C, and by the 5th day of life - up to 37 "C. Usually in the first days of life in a healthy newborn, temperature instability is noted, its rapid changes during swaddling, after feeding. Over the next days, the body temperature in newborns remains unstable and only gradually (by 1.5-3 months) is the temperature curve established characteristic of healthy infants.For a long time, the body temperature in children usually remains 0.3-0.4 "C higher than in adults, and only gradually sets at the level of adults. The decrease in temperature in the first hours after birth is called transient hypothermia of the newborn. It is due to the action of a lower than in the womb, ambient temperature and the immaturity of the mechanisms of thermoregulation. In children born physiologically immature and (or) premature, as well as in patients, more pronounced hypothermia is observed, which persists for several days.

Rectal temperature in children is usually 0.3-0.5 ° C higher than the skin temperature, measured in the armpit or in the groin. After exercise, especially after running, long walks and other loads, a temporary increase in rectal temperature in children is greater than axillary temperature, and the temperature difference in these areas can reach 1 ° C or more. At the same time, children have a local rather than a general increase in body temperature. The higher rectal temperature is explained by abundant blood flow in this area, the proximity of heat-producing large muscle masses, and heat production by bacterial microflora.

The nature of daily fluctuations in body temperature, or circadian rhythm, varies in different children, but is relatively constant in an individual. The circadian rhythm is absent in newborns and young children and is established after the second year of life. It is more pronounced in children than in adults. The lowest body temperature is observed at about 3 am, and the highest - from 17 to 18 hours. The difference between the highest and lowest points of the temperature cycle in children is greater than in

adults. This difference in children can reach 1.4 ° C. Daily temperature fluctuations are more significant in girls than in boys. The range of temperature fluctuations during the day at a stable ambient temperature in the first days of life is about 0.3 "C, by 2-3 months it increases to 0.6 ° C and by 3-5 years - up to 1 ° C. The magnitude of temperature fluctuations of the body depends not only on age, but also on the ambient temperature, physical activity, emotional state of the child, the quality and quantity of food taken, the functional state of the endocrine system, as well as other factors affecting the basal metabolism, motor activity, vascular tone. Knowing the normal diurnal changes in temperature helps the clinician avoid misinterpreting the causes of a mild physiological increase in evening temperature and perceiving it as a manifestation of hyperthermia or fever.The same applies to the reasoning about "subnormal temperature" in the early hours of the morning.

Cyclic daily fluctuations in body temperature in a healthy child are established by 1.5-2 months of life, which coincides in time with the formation of daily rhythms of heart rate and respiratory rate. In premature babies, the daily temperature cycle is established much later than in full-term babies. Preservation of the normal circadian rhythm of temperature in children with brain diseases may indicate that the central mechanisms of thermoregulation are not damaged in them. At the same time, if no other reasons have been identified to explain the absence of a circadian rhythm in a child, this makes it possible to suspect the presence of a false fever.

The relative insufficiency of heat production in newborns, and especially premature ones, requires the creation of an optimal temperature environment for them - a thermoneutral zone. Its boundaries are the temperature range of the air surrounding the child, at which normal body temperature is maintained with a minimum tension of the TP mechanisms. If for healthy naked newborns born on time, the boundaries of the thermoneutral zone are 32-35 ° C, then under these conditions for a very premature baby - 35-36 "C. For swaddled newborns, the temperature boundaries of this zone are shifted to 23-26 - ° C and 30-33 ° C, respectively. By the age of one month, the temperature indicators of the thermoneutral zone shift down by 1.5-2 ° C, and the width of their range increases by 0.3-0.5 ° C.

In healthy newborns, there is practically no decrease in body temperature below 36-36.1 ° C. A decrease in temperature below this level usually reflects the failure of energy metabolism and is observed, as a rule, with malnutrition of I-III degrees, severe heart and vascular insufficiency, insufficiency of the liver, kidneys, decreased function of the thyroid gland, adrenal glands, with hypoglycemia and other serious diseases. Body temperature drops sharply in anaphylactic shock, collapses of allergic origin.

Changes in body temperature in children can be caused by various reasons. Prolonged exposure to cold or heat may be uncompensated by still insufficiently mature mechanisms of thermoregulation and lead to a significant increase (exogenous hyperthermia) in body temperature or its decrease (exogenous hypothermia), which often occurs in preterm and immature children.

Newborns easily overheat when the air temperature rises, which is due to their low body weight, the proximity of the temperature of the thermal indifferent zone and body temperature, and the low functional activity of the sweat glands. Overheating is also facilitated by excessive restriction of heat transfer by clothing.

Under the action of low air temperature in newborns, heat production increases, but the intensity of this reaction is often insufficient to maintain normal body temperature, especially with prolonged exposure to cold. The maximum increase in heat production in newborns does not exceed twice the value of the basal metabolism (in an adult, heat production during cooling can increase for a short time by 3-4 times).

Thus, among the most important features of thermoregulation in newborns, one can distinguish: a higher level of heat transfer in relation to heat production; limited ability to increase heat transfer during overheating, as well as to increase heat production during cooling; inability to respond with a feverish temperature reaction due to the weak sensitivity of hypothalamic neurons to the action of leukocyte and other endopyrogens and the high concentration of arginine-vasopressin in the blood, which reduces body temperature. A feature of thermoregulation in newborns is the absence of reactions to increase thermoregulatory tone and cold shivering with a decrease in body temperature. With rapid cooling, they have a variety of uncoordinated movements, accompanied by a cry. This reaction serves as a signal to the mother to eliminate exposure to cold.

A newborn child is so tiny, so fragile, tender and touching that you want to protect him all the time, to do something for him. This instinct is designed to protect the baby, but in our civilized time, it often greatly harms the health of the child. A typical picture in the maternity hospital: a temperature of 24 degrees and a bag of a baby, a diaper, a suit or bodysuit, and two diapers. In more benign cases, they are limited to a suit, a hat and a blanket. As a result, many babies come home with red skin and prickly heat. I confess that my first child arrived in this form.

Content

Why is it necessary to temper children from the first days of life?

Your most wonderful baby in the world lived in your tummy in warmth and comfort. His body did not bother to deal with the issues of moisturizing, cleansing, heating and cooling. But now he was born and many different sensations and problems fell upon his body. And your main task is to teach all body systems of your little miracle to respond quickly and adequately in order to be able to protect yourself.

All my three children during the first year of life were ill only once, and that because I infected them. But, surprisingly, while I suffered with laryngitis for two weeks, they were sick for no more than a week. After a year, their illnesses were reduced to a slight runny nose, maybe a cough, about twice a year. I never worry about their clothes - even if they walk naked down the street, if they are not cold, I never forbade climbing in puddles in the spring, at home they only go barefoot, without socks, without slippers, someone in pants and a jacket, someone in shorts. At the same time, we have no more than 18 degrees at home.

I was raised according to the standard rules - warm clothes, warm hat, warm shelter, fear of drafts. Under these seemingly optimal conditions, I managed to end up in the hospital with pneumonia at the age of three. All my childhood, as long as I can remember, I was sick. In adolescence came with chronic tonsillitis. And now I get sick an order of magnitude longer and more difficult than they do, and I freeze them much faster. I didn’t want this for my children, so I taught their body to react correctly to the cold already in the hospital.

Read also:

How does thermoregulation work in babies?

A newborn baby is born with an effective thermoregulation system, it's just different from the system of an adult. This is done by nature specifically so that the baby has the opportunity to form a new system of thermoregulation and immunity from scratch, ideally suited to the conditions in which he will live. If you keep wrapping up a child and he is on the verge of overheating, then this new system is formed as if he lives in some equatorial climate. The body will not cope well with cooling, which will constantly affect the immune system. Hence the frequent colds.

So, in a newborn, brown subcutaneous adipose tissue, which is located between the shoulder blades, on the chest, on the neck, near individual organs, is responsible for heating the body. It is formed from the 26th week of pregnancy specifically for the moment when the miracle of birth will occur. If the baby is cold, then in this adipose tissue, the processes of fat oxidation begin to actively occur with the release of energy - the body heats up. A simple but effective mechanism of heat production.

If brown adipose tissue does not cope, then the property of muscle tissue to create heat during work is connected to the work. The baby wakes up, starts crying and moves actively. If this does not help, then after the depletion of all the reserves of nutrients in the body, the newborn becomes silent, stops moving, the body begins to cool rapidly and death may occur.

But there are not so many opportunities to deal with overheating. Sweat glands still work poorly, and the layer of clothing prevents the sweat from evaporating. And it is completely impossible to stop the production of heat, because it is produced all the time as a result of many oxidative reactions occurring in the body. These reactions are necessary for the nutrition of cells, for the creation of new cells, for the transition of one substance to another. Heat is also emitted from the constant movement inside his body - blood moves, internal organs move, cells move.

An overheated baby becomes inactive, hot, wet, he does not even have the strength to cry. After all, now his body saves on movements. If you do not help him, then the body begins to collapse and everything can end in death. In milder forms, we observe overheating in the form of prickly heat or a sudden illness.

As the child grows older, the thermoregulation system in an infant changes, becoming the same as in adults. The hypothalamus matures and takes on the responsibility of maintaining a constant body temperature. He now has a wide range of tools at his disposal: the creation of a subcutaneous fat layer, hormones, nutrients from the digestive system, sweat glands, muscles, etc. So, the task of parents is to teach the hypothalamus to master these tools perfectly. For this, it is necessary to harden the child from the first days.

How to temper?

In general, there are many methods of hardening. You choose the method that best suits you due to your lifestyle and living conditions. But there are a few general rules that must be observed regardless of the technique:

• If a newborn is cold, his nasolabial triangle turns blue, he screams, twists his arms and legs, trembling may begin, his thighs are cool to the touch. But the nose, arms and legs should normally be cool, because. they are wet all the time.
• If the baby is hot, then his back, neck, armpits become wet, his face and body turn red, he becomes lethargic, sleepy. With severe overheating, the baby can go into hibernation for several hours, which allows him to reduce all reactions in the body.
• Any tempering procedure should not cause a crying attack in a child. If you lowered the temperature in the bath and the baby began to cry, then rather get it out and soothe, and next time lower it a little less.

I did something like this:

In the maternity hospital itself, we were all forced to measure the temperature of the babies, and the first days after the arrival of the first baby from the maternity hospital, I regularly measured his temperature in order to know how it changes depending on how I dressed him. I determined the well-being of the second and third child with my hand and vision.

The cap on the head does not need to be worn if the room temperature is above 20 degrees. They looked askance at me in the maternity hospital, because my children (except for the first one) lay in a light suit and without a cap (the temperature in our room was 24 degrees), and after changing the diaper, they lay naked on a diaper for some time - aired.

When changing a diaper, do not rush to dress the baby - let the skin breathe a little. The vessels of the body learn to narrow in order to save heat. We had a temperature of about 22 degrees at home, but in the village it was 18-19 degrees - I still had them naked.

If it’s 30 degrees and above outside, then neither a blanket nor a closed suit is needed for a walk. It is best for the baby to ride in his stroller in one diaper. Pampers can also be unzipped so that the crotch does not sweat.

It is not necessary to wash the baby in water with a temperature above 36 degrees. It is better to gradually reduce the temperature, bringing it to 28 degrees. I didn’t even wash newborns at 37 degrees. I have never boiled water. Only potassium permanganate was added in the first two weeks.

At the end of bathing, pour cold water into the bath from the side of the legs so that the temperature in the bath decreases - such a contrasting procedure is more gentle than dousing with cool water. I lowered the kids into the bath in a diaper - so they were less frightened and rarely flinched from the cool water. After lowering the diaper just sank to the bottom.

Komarovsky writes about hardening well in his books, but there are other less fashionable methods. Though I didn't follow his books as clear instructions.

In general, in hardening, I have always been of the opinion (and now I am): if he feels fine, does not complain, then he is not cold. My second child was born at the end of May, and in mid-June the swimming season began - we also circled his little body in the water in the river (there were a lot of sidelong glances). By the way, during pregnancy, I did not deny myself the pleasure of swimming in the river, even in the last months (the eldest was born in mid-September). Although I have never seen pregnant women swimming in a pond. So I guess I'm the only one.