Rules for acclimatization in cold climates. Acclimatization of a person in various climatic conditions: how to pass it. The acclimatization process is divided into two stages

The problems of acclimatization to hot climate conditions are of great practical importance, connected with the migration of the population of the Soviet Union to subtropical regions and the development of dry deserts, as well as in view of the expansion of international relations and the tasks of rendering assistance to developing countries. When moving to a temporary or permanent place of residence in hot climate areas, a person experiences its influence on all physiological functions. How successfully the body adapts to these conditions depends on its health and performance. Therefore, knowledge of the patterns and properties of restructuring of the main functions in the process of acclimatization is important for facilitating and creating optimal working and living conditions. The study of the dynamics of adaptive changes in the functions of the human body in a dry hot desert made it possible to distinguish four phases of the acclimatization process. First the phase of overcompensation is characterized by a violent reaction of breathing, circulation, sweating and other functions and carries elements of non-specific tension - stress. In second phase, the functions are restructured in relation to new conditions by reducing excessive reactions to the level required by the new state of homeostasis. IN third , which is called the phase of energy adaptation, the body adapts to a more economical way of functioning, limiting the loss of water and salts with sweat, reducing energy expenditure on muscle work, etc. Finally, fourth the phase completes the process of acclimatization with the stabilization of new homeostatic parameters based on the rebuilt nervous and humoral regulations in relation to hot climate conditions.

The duration of these phases is extremely variable both individually and in relation to different functions. Cases are described when all indicators of heat transfer and hemodynamics of people who arrived from the Moscow region in Central Asia, after 20 - 30 days

rebuilt to a level close to the performance of local residents (P. A. Solomko, 1960). Along with this, there were also much more

long periods of acclimatization, especially in terms of metabolism, some of which stabilize at a new level

only a few months later (F. Sulman, N. Hirshman, I. Pfeifer, 1962).

The study of the mechanisms of the changes occurring at the same time showed that in the initial stage of acclimatization, non-specific reactions develop urgently, using humoral mechanisms, with the formation of sympathetic amines and corticosteroids, which reduce the sensitivity of tissues to temperature and cause a general increase in the body's resistance. Then comes the stage of development of specific thermoregulatory reactions, and urgent non-specific, expensive for the body, decline. The rate of acclimatization also depends on the climate in which the visitors lived before. So, exposure to the sun on the day of arrival in Tashkent caused sweating in those who came from the northern regions of the Soviet Union 10 times, and in those who arrived from the middle lane 4 times more than in local residents, but after two years of acclimatization, the amount of sweat emitted by everyone became the same One of the important manifestations of acclimatization is to increase the efficiency of heat transfer. For example, during 30 days of adaptation to work in the desert, the amount of sweat increased (in the first days - 6.25 liters, on the 30th day - 7.09 liters), the beginning of its release accelerated (on the forehead: in the first days - after 7 2 min, on the 22nd day - after 3.0 min), the proportion of excess uselessly flowing sweat decreased (in the first days - 80%, on the 24th day - 40%). Such an increase in heat transfer due to an increase in the efficiency of sweating makes it possible to reduce the heating of the body during intense physical exertion in the desert (rectal temperature in the first days - 39.4 ° C, in the last days - 38.2 ° C). Sweating during adaptation to heat increases mainly by increasing the number of working glands, and not by increasing the secretion of each of them. During acclimatization, the areas of intense sweating are redistributed towards the extremities, which are more favorable for heat transfer in relation to the mass to the surface and the presence of peculiar arteriovenous heat exchangers. As a result of 18-35 days of adaptation to heat, the proportion of sweating on the extremities increases from 28-42% to 34-54% of the total sweat. Changes in sweating are always preceded by vascular reactions. In the process of acclimatization, the loss of salts with sweat decreases. So, in the first two days of being in a hot, dry climate, the notes contained 0.63% chlorides, and by the end of the month only 0.21%; the total daily loss of chlorides with sweat on the first day was 40.0 g, and by the end of the month - 15.6 g. After 2 years of living in a hot dry climate, the water-salt metabolism of visitors is practically comparable to that of local residents

In the process of acclimatization, the restructuring of the circulatory system is primarily aimed at increasing the transfer of heat generated in the body to its skin surface. This is achieved by increasing the volume of circulating blood and expanding the bed of skin vessels. However, as already noted, in the first phase of acclimatization, excessive reactions occur, and their further dynamics often takes on a phase character.

In 20 men aged 18-21, who first arrived in the hot regions of Central Asia, blood pressure in the first three days after arrival fluctuated within 115-120 mm Hg. Art. (maximum) and 70-80 mm (minimum); after 7 days, in 15 of them, the pressure decreased to 100 and 65 mm Hg, respectively, and only after 4-5 months, in all the subjects, the pressure stabilized at the level of 110 and 70 mm, characteristic of local residents. Observations of the acclimatization of visitors to Tashkent showed that the decrease in the maximum and minimum arterial

In the first days of acclimatization, visitors from the middle zone experience an increase in heart rate. Such tachycardia is observed in 360 people who arrived from the Moscow region for work and the Karakum desert, and in young healthy people who came to Turkmenistan. However, with acclimatization, the heart rate returns to the original average values. This circumstance, and the absence of tachycardia during a gradual transition from a temperate to a hot climate, observed, for example, when traveling from Germany to Central America, lead to the conclusion that an increase in heart rate occurs as a temporary reaction to acute exposure to high temperature. In a humid tropical climate, tachycardia and a sharp drop in blood pressure can cause a person who has not had time to acclimatize to a serious condition with loss of consciousness.

The acclimatization of inhabitants of a temperate climate, who find themselves in the conditions of the tropics, is also reflected in the composition of the blood. So, Europeans who lived 22 - 36 months in tropical Africa (Guinea) had a significantly reduced formation of red blood cells and a reduced hemoglobin content, like the native Africans. The loss of a large amount of salts during intense sweating violates the salt composition of the blood. However, in the process of acclimatization, regulatory mechanisms are formed that eliminate these disturbances and ensure the osmatic properties and ionic balance of blood necessary for life in new conditions. The effectiveness of these regulations is evidenced by the results of experiments with a two-hour exposure to the sun for people who are to varying degrees adapted to the heat. There were no significant changes in the electrolyte composition of the blood among local residents, among visitors from the middle zone, the sodium content in the blood increased by 22.1%, and among those who arrived from the northern regions - by 70%, the potassium content decreased by 19.7 and 23%, respectively. .

In the complex issue of the physiological mechanisms of acclimatization, there are still many ambiguities, there is no consensus about their nature and adaptive significance. Some researchers consider the reactions that develop during adaptation as a manifestation of a nonspecific adaptive syndrome. However, their interconnectedness and the sequence of development have a specific character of a mechanism of a certain purposefulness, which maintains the constancy of the internal environment of the organism in a hot climate. These conditions are characterized by difficult removal of excess endogenous heat, to which a significant amount of exogenous heat is added, which raises the main homeostatic task of maintaining a constant body temperature by increasing heat transfer. First of all, there are circulatory reactions that carry endogenous heat to the surface of the body.

However, they are unable to solve this problem. Then the main method of enhancing heat transfer is activated by evaporation of large masses of sweat. The resulting loss of a significant amount of water and salts, in turn, poses a new homeostatic task of maintaining the constancy of isotonia and isotony of the internal environment. More and more body functions are involved in the process of solving problems of homeostasis, shifts in the parameters of which pose ever new tasks of maintaining their constancy. Thus, a complex chain of interrelated adaptive reactions is formed, which

are organized by neurohumoral control mechanisms rebuilt to maintain a different level of homeostasis adequately to the new ones

climatic conditions. Restructuring occurs mainly in the nerve centers of thermoregulation, vasomotor, cardiac activity, sweating and endocrine systems of the pituitary gland, adrenal glands, thyroid gland, which are interconnected through the hypothalamus and its neurosecretory structures.

Since the forced removal of heat by blood from the depths of the body to the skin vessels begins before its temperature rises, it can be assumed that the mechanism of these circulatory reactions is associated with reflexes from skin thermoreceptors with altered excitability of the centers of regulation of the lumen of blood vessels and cardiac activity. In the process of acclimatization, a conditioned reflex mechanism is inevitably formed to activate the reactions of expansion of skin vessels and an increase in the minute volume of blood pumped by the heart. With a good functional state of the heart, the minute volume increases due to an increase in systolic recoil, and with relative weakness of the myocardium, due to an increase in systoles. The absence of seasonal fluctuations in minute volume may indicate the completion of the process of acclimatization to a dry hot climate. These rearrangements of blood circulation through vascular receptors and hypothalamic centers cause reactions of humoral regulators, primarily hormones of the pituitary and adrenal glands.

Sweating can also begin as a conditioned reflex, according to various signals from the external environment, but after the appearance of a circulatory reaction. Then the basic reflexes from the thermoreceptors of the skin, internal organs and centers of the hypothalamus come into play. The latter are of particular importance at the beginning of acclimatization, when perspiration is caused only by an increase in body temperature. It has also been suggested that local heating of the skin by direct action of heat or release of mediators in the endings of the sweating nerves can excite the activity of the sweat glands. In the process of adaptation of sweating to hot climate conditions, hormonal regulatory mechanisms, in particular the activity of the adrenal cortex, play an important role. The increased loss of water and salts as a result of increased sweating causes an intensive release of aldosterone, which limits the excretion of sodium in the urine and, possibly, affects the composition of sweat, reducing the concentration of salts in it. However, there is an opinion that the latter cannot be considered proven. From the point of view of some scientists, changes in the salt composition of sweat are determined by the water-electrolyte state of the skin. Evaluation of the activity of the adrenal cortex in the excretion of 17-hydroxycorticosteroids with urine showed their possible participation in the mechanism of adaptation to a hot climate. It was found that after three months of acclimatization, the hydrocortisone fraction increased by 3 times, and the activity of Prehydrogenase and liver reductases decreased. However, the author notes that after 15 months these indicators are restored. A functional test with a load of adrenocorticotropic hormone showed a decrease in glucocorticoid and androgenic functions of the adrenal glands. The question of the role of the thyroid gland in the mechanism of adaptation to high external temperatures is complicated due to the absence of seasonal changes in thyroid activity according to the protein-related code. Therefore, it was suggested that its influence on metabolism is carried out indirectly under conditions of an altered sensitivity of energy processes in mitochondria.

A certain relation to the mechanism of acclimatization is the influence of the adrenoglomerulotopic hormone of the pineal gland, which, together with aldosterone, "preserves" water and salts in the body. Apparently, mast cells associated with such humoral metabolic regulators as histamine, serotonin, heparin and others are also involved in this mechanism, since in animal experiments adaptation to high external temperature was expressed by a decrease in their stress reactions.

Observations of metabolic reactions in subjects who are in a heat chamber at 34 - 36 ° C and a relative humidity of 80% showed that with a low-calorie daily diet (1800 calories), the glucocorticoid functions of the adrenal cortex and energy expenditure are reduced, and with a high-calorie diet (4000 calories) they increase. These results may be the basis for recommending caloric restriction as one of the means of facilitating adaptation to hot climates. Although the mechanisms of acclimatization rearrangements of the physiological functions of a person who finds himself in a hot climate are not fully understood, the available information and popular experience give grounds for recommendations that contribute to faster and more effective acclimatization. First of all, large thermal loads should first be avoided, which can cause thermal shock and irreversible breakdown of the adaptive thermoregulation system. Acclimatization occurs most effectively with a gradual increase in such loads. It is necessary to remember about similar reactions of the body to a high external temperature and to muscle work.

Therefore, on the one hand, during physical work in the heat, the body experiences a dangerous double load, and on the other hand, practice has shown that the most effective acclimatization is achieved with a combination of gradually increasing temperature and moderate physical exertion. Some researchers believe that women, for a number of reasons, find it more difficult than men to acclimatize in hot zones. About the features of dwellings and clothing, daily routine and nutrition in the south, it was said above. To this we can add that for successful acclimatization it is also necessary to facilitate heat dissipation by hygienic skin care, cool showers, protection of the eyes with smoky glasses and covering the head from direct sunlight.

Acclimatization is the process of gradual adaptation of the human body to new climatic conditions. Acclimatization is based on the body's ability to adapt (rebuild) to new conditions in order to ensure the constancy of the internal environment (body temperature, blood pressure, metabolism, etc.). In the process of acclimatization, a person's well-being worsens to a certain extent, fatigue appears and efficiency decreases. The more the climatic conditions of the new place of residence differ from the usual ones, the worse a person is prepared for life in new conditions, the more difficult and longer the process of acclimatization proceeds.

Acclimatization during a change of residence is inevitable, since any organism reacts to changes occurring in the external environment, and adapts to them. But different people acclimatize in different ways. It has been noted that healthy, hardened people with good physical fitness adapt to new conditions of existence faster and with less deviations. In addition, a more successful acclimatization is facilitated by the ability of a person to change his mode of life, clothes, food and bring them in line with new conditions, using the experience of local residents.

Therefore, for the rest, which will take place in other climatic conditions, one must prepare and try to do everything to help the body quickly adapt to new conditions. In order to increase the body's ability to quickly acclimatize, constant and intensive physical training is necessary long before the trip. Daily exercise, hardening procedures, running, skiing, hiking - all this greatly increases the adaptive capacity of your body.

Arriving at the resting place, do not rush to immediately get all the pleasures in one day, constantly monitor your well-being and opportunities, do not overload yourself with excessive exposure to the sun, excessive and repeated bathing, plan your loads wisely. Do everything in moderation. For example, consider some features of acclimatization in different climatic conditions.

Acclimatization in cold climates

Acclimatization in a cold climate, especially in the Far North, is associated with adaptation to such factors as low air temperatures, strong winds, and violation of the light regime (polar night and polar day). Acclimatization here can last for a long time and be accompanied by excessive fatigue, irresistible drowsiness, loss of appetite. As a person gets used to new conditions, these unpleasant phenomena disappear.

Proper nutrition helps accelerate acclimatization in cold climates. At this time, the calorie intake should be increased compared to your usual diet. Food should contain the necessary set of vitamins and minerals. In a cold climate, clothing should have increased heat-shielding and windproof properties.

Acclimatization in a hot climate

Hot climate conditions may vary. Thus, the subtropics and tropics are characterized by high temperature, humidity and solar radiation; for desert zones - high temperature, solar radiation and low air humidity. The beginning of acclimatization in a hot climate may be accompanied by muscle weakness, palpitations, and increased sweating. In hot climates, the likelihood of heat and sunstroke increases.

Heat stroke (a condition that occurs with general overheating and is characterized by fatigue, headache, weakness, dizziness) is most likely to occur at high temperature and humidity. Under these conditions, the body's heat exchange with the environment is disturbed - the body overheats.

Sunstroke can happen if you stay in the sun for a long time with your head uncovered. The effects of sunstroke are no different from those of heatstroke.

To avoid these and other troubles, it is important from the first day to adapt your regimen to local climatic conditions. To do this, you should carefully look at the clothes and daily routine of local residents. In the heat, it is better to wear light-colored clothes made of cotton, and wear a light white headdress on your head. On a hot day, you need to be in the shade more often, in the hottest time (from 13 to 16 hours) you can sleep.

Don't get too carried away with tanning. It is better to sunbathe in the morning with a gradual increase in the dose of sunbathing.

To acclimatize faster it is very important to observe the water-salt regime, which provides a normal ratio between the amount of water and mineral salts entering the body and excreted from it.

Drink in the heat not only to quench your thirst, but also to compensate for the loss of water and mineral salts, which leave the body with sweat. You need to drink slowly, in small sips. You can drink mineral water, tea quenches thirst well.

Let us draw your attention to a few general provisions to ensure accelerated acclimatization when changing climatic conditions. In the first days of your stay in a new place, do not overload yourself with various activities, especially if the trip was associated with a change in time zones. Let the body get used to the new conditions for two to three days.

Follow the drinking regime taking into account local conditions and the needs of your body. Do not get carried away with local cuisine, you can try them, but in nutrition it is better to stick to familiar foods. Observe the measure in everything. Constantly monitor your health and physical condition. Do not do anything through force and without desire.

The main goal of your trip is not to set a record at any cost, but to get to know the world and improve your health.

Test yourself

■ What is acclimatization and how does it manifest itself?
■ What factors primarily contribute to the rapid acclimatization of a person in new conditions?
■ What are the features of acclimatization in a hot climate?
■ Are you fit enough to travel to a hot country?

After lessons

Consider how to avoid heat stroke and sunstroke in hot climates. Record the recommendations in your safety diary.

Think about the safety precautions you need to take in cold climates. Pick up examples from popular science and fiction. Develop recommendations for yourself in matters of clothing, daily routine and nutrition in case you find yourself in places with a cold climate.

Additional material

Low temperatures, high relative humidity, high air velocity, long polar night with magnetic storms and auroras, short summer, long winter, decrease in the spectrum of sunlight, the predominance of the ultraviolet part, a small amount of precipitation, a decrease in the density of O 2 in the air, slightly mineral. water, a special combination of micro and macro elements in local products, an increase in the consumption of canned food and concentrates. Visitors have:

sleep disturbance, increased fatigue, reduced performance, pain of various localization, vegetative-vascular disorders;

anxiety of varying severity (from psychological discomfort to a neurotic breakdown (deaptational neurosis);

chronic hypoxia syndrome (due to frequent and sharp fluctuations in atmospheric pressure, a decrease in the density of O 2 in the air);

polar shortness of breath (decreased VC, external respiration functions are not enough to provide the body with O 2);

shifts in carbohydrate, lipid metabolism -> hypercholesterolemia;

cardiac complaints (pain in the heart, palpitations, shortness of breath), arterial hypertension;

violation of vitamin status -> deficiency of water-soluble vitamins;

caries, hypertrophic gingivitis, early stages of periodontal disease;

hypocidic gastritis (decreased secretory activity of the gastric mucosa);

complications of pregnancy (early and late toxicosis, anemia of pregnant women);

wound healing is slowed down by 2-2.5 times;

exacerbation of chronic diseases.

When addictive: metabolism, heat production, bcc increase, skin temperature recovers faster when hypothermia. Activity:

Dense development along the perimeter, compact development, placement of buildings with their ends to the prevailing winds, covered passages between buildings.

Large area of ​​​​premises, convenient, comfortable, pace. greater than 22, window orientation.

The first floors of the house should be non-residential.

Winter gardens indoors.

Nutrition: the energy value of the daily diet should be increased by 15-20%, the amount of proteins by 15-18%, fat by 20-25%. Inclusion in the diet of wild plants, early vegetables, decoctions of wild rose, needles; correct diet. Proteins of animal origin - 60%.

Clothing - low thermal conductivity, sufficient vapor conductivity and breathability. The outer layer of clothing should prevent moisture from sweating and have windproof properties. Materials: fur, wool. Shoes are 2-3 sizes larger. Goggles for eye protection.

Correct regulation of work and rest, mode of life.

UFO in fotaria, in production, children's institutions.

Hardening procedures, sports.

Anti-relapse treatment of chronic diseases.

Sanitation of the oral cavity, treatment of local foci of infection, deworming

24.. Diseases associated with the action of high atmospheric pressure, prevention.

In some industries, there are types of work that are performed under conditions of high atmospheric pressure. This factor is considered as occupational hazard, since it can lead to pathology.

Work associated with staying in conditions of high atmospheric pressure can lead to the development of decompression (caisson) sickness.

It occurs in divers, workers involved in the construction of bridge supports, sinking of flooded mine shafts and other structures in water-saturated soils or under water. Caisson work is also carried out in the construction of foundations for buildings and equipment, in the construction of subway tunnels. The caisson method consists in draining water from a closed space where work is carried out. Compressed air is injected into this space, which squeezes out water and allows work to be carried out.

Pathogenesis. There are three stages of processes occurring in the body as a result of the action of increased atmospheric pressure:

1. When diving. The pressure is rising. When breathing in an environment with high pressure, the tissues of the body are saturated with gases. The main part of the total pressure of gases in the lungs and, consequently, in the blood and tissues is accounted for by nitrogen, a physiologically inert gas that does not participate in gas exchange. While the oxygen entering the body under increased pressure, dissolving in liquids and tissues, is largely absorbed, nitrogen only physically dissolves in the tissues and gradually saturates them. Saturation of liquids and tissues occurs until equilibrium is reached and the pressure of nitrogen in them is equal to its partial pressure in the environment. Different tissues of the body are saturated with nitrogen at different rates. Nitrogen is poorly soluble in the blood, but very well in the nervous tissue, subcutaneous fat. In this case, a person feels a headache, toothache, sinus pain, tinnitus, flatulence, tinnitus, dizziness, weakness.

2. Work in a caisson. Atmospheric pressure is consistently high, dissolved nitrogen is in equilibrium. At the same time, a person is forced to work in an unfavorable microclimate (high or low temperature), at a pressure above 3 atmospheres, the narcotic effect of nitrogen is manifested.

3. Rise to the surface, decrease in atmospheric pressure. During decompression, the reverse process occurs in the body - the removal of nitrogen dissolved in them from the tissues (desaturation). With a rapid decrease in excess pressure, nitrogen passes from a dissolved state to a free gaseous state. Not having time to diffuse through the lungs, it forms gas bubbles that clog and break blood capillaries, irritate nerve endings, deform and damage body tissues. In this case, the pathological process is most often localized in the subcutaneous fat, bones and joints, in the tissues of the nervous system. The decompression sickness actually develops. Symptoms depend on the location and number of emboli: itching, burning, chills, myalgia, arthralgia, severe fatigue, in severe cases Meniere's syndrome. Meniere's syndrome is caused by a gas embolism of the vessels of the labyrinth of the inner ear. Manifestations of the syndrome are dizziness, noise and ringing in the ears, hearing loss, nausea, vomiting. Against this background, patients complain that all objects rotate before their eyes; a slight turn of the head intensifies the painful phenomena. Then severe pallor, sweating, weakness appear, horizontal nystagmus, bradycardia are determined on examination. Possible loss of consciousness.

Prevention:

1. Slow compression.

2. Regulation of the operating time in conditions of high atmospheric pressure.

3. Slow decompression.

4. Replacement of nitrogen with helium, which dissolves in the blood at high pressures.

5. Mandatory professional medical examinations (preliminary and periodic). Preliminary examinations determine the suitability of workers for work in hazardous working conditions. Periodic inspections provide monitoring of the health status of workers, help to identify the initial signs of a chronic occupational disease.

Diseases associated with exposure to low atmospheric pressure, prevention.

Atmospheric pressure - the pressure of the atmosphere on all objects in it and the Earth's surface. Atmospheric pressure is created by the gravitational attraction of air to the Earth.

Normal atmospheric pressure is 760 mmHg at sea level at 0°C, which corresponds to 101,325 Pa.

The effect of lowering atmospheric pressure at different altitudes above sea level:

Up to 2000 m above sea level. A decrease in atmospheric pressure does not affect the human condition.

2 km is the reaction threshold. The manifestation of the first changes in the body, determined only with the help of equipment

Up to 4 km above sea level: full compensation zone.

4 km is the threshold of violations. The first external manifestations

5-6 km: zone of incomplete compensation

6 km: critical threshold

7-8: critical zone

8 km: threshold of death

Rising to a height of 4 km or more, a decrease in atmospheric pressure and, accordingly, a decrease in the partial pressure of oxygen in the inhaled air, leading to a decrease in hemoglobin saturation with oxygen and hypoxia of the body, contributes to the development of a symptom complex in people known as altitude sickness.

It occurs, as a rule, among pilots and climbers in the absence of measures that protect against the influence of low pressure.

Altitude sickness first manifests itself in dizziness, headache, impaired attention, concentration, coordination, euphoria due to hypoxia of the brain and the body as a whole. Due to euphoria, inexperienced people overestimate their strength and climb higher and further. Then euphoria is replaced by depression, a decrease in general sensitivity, a decrease in working capacity, weakness. With continued decrease in atmospheric pressure, death occurs.

Prevention:

1. Use of oxygen devices and high-altitude compensating suits when lifting.

2. Slow rise with stops to adapt the body.

3. Proper nutrition (exclusion from the diet of fiber and fat).

4.Preliminary and periodic medical examinations. Preliminary examinations determine the suitability of workers for work in hazardous working conditions. Periodic inspections provide monitoring of the health status of workers, help to identify the initial signs of a chronic occupational disease.

25.Air temperature and humidity, significance for the body, measures to prevent adverse effects.

Air temperature.

To consider the influence of air temperature on the human body, it is necessary to recall the main mechanisms of thermoregulation. As you know, the body's heat exchange is maintained by balancing the processes of chemical and physical thermoregulation. Due to chemical thermoregulation, the intensity of metabolic processes changes: the accumulation of heat in the body occurs as a result of the oxidation of nutrients and the production of heat during muscle work, as well as from the radiant heat of the sun and heated objects, warm air and hot food. As a result of physical thermoregulation, the processes of heat transfer change by convection, radiation, evaporation and conduction. Heat transfer by conduction is carried out in contact with cold surfaces; convection - by heating the air adjacent to the body; radiation - infrared radiation to colder surrounding objects, which does not depend on the ambient temperature; evaporation - the release of heat with sweat. Due to the regulation of the processes of heat generation and heat transfer, a person is able to maintain a constant body temperature with significant fluctuations in air temperature, however, the limits of thermoregulation are not unlimited, and their transition leads to a violation of thermal equilibrium, sometimes with deep pathological changes (overheating or hypothermia). Overheating Prevention:

Rational clothing (natural fabrics, hygroscopic, moisture resistant, etc.)

Unlimited water consumption

Restriction of stay in conditions of high temperature

In room

Installation of air conditioners

Prevention of hypothermia:

A) rational clothing (multi-layered, warm and windproof)

B) rational shoes (thermoplastic sole, 1-2 sizes larger)

2) restriction of stay on the street

3) hot high-calorie meals and tea before going out

In room

Ventilation

Heating

Air humidity.

In hygienic practice, the most important is the relative humidity of the air, which shows the degree of saturation of the air with water vapor. It plays an important role in the body's thermoregulation. At high humidity, heat transfer becomes difficult or increases depending on the air temperature. At low humidity (10-15%) there is a more intense about \ this temperature.

The dew point is the temperature at which water vapor condenses.

Humidity deficit - the difference between saturated vapor pressure and vapor pressure, that is, between the maximum and absolute humidity of the air.

To prevent the adverse effects of humidity on the human body in the room, it is necessary to install a rational air conditioning system in it.

26. The speed and direction of air movement, the value for the body. Features of air movement in rooms of various types. Measures to prevent adverse effects.

As you know, the air is almost constantly in motion, which is associated with the uneven heating of the earth's surface by the sun. The difference in temperature and pressure causes the movement of air masses. The movement of air is usually characterized by direction and speed. It is noted that each locality is characterized by a regular frequency of winds predominantly in one direction. To identify the patterns of directions, a special graphic value is used - a wind rose, which is a line of rhombuses on which segments are plotted corresponding in length to the number and strength of winds of a certain direction, expressed as a percentage of their total number. Knowledge of this pattern allows you to correctly carry out the relative position and orientation of residential buildings, hospitals, pharmacies, sanatoriums, industrial enterprises, etc.

The speed of air movement is determined by the number of meters it travels per second. The speed of movement of air masses plays a significant role in the processes of heat transfer of the body.

Air mobility affects the body's heat loss through convection and perspiration. At high air temperatures, its moderate mobility helps to cool the skin, at low temperatures it leads to hypothermia and increases the risk of frostbite. Frost in calm weather is more easily tolerated than in strong winds. The most favorable mobility of atmospheric air in summer is 1-5 m/s. In residential and public premises, the air velocity is normalized within 0.2-0.4 m/s. The speed of air movement affects the distribution of harmful substances in the room. Air currents can distribute them throughout the room, transfer dust from a settled state to a suspended state.

Air movement value:

Effect on heat transfer

Influence on the emotional state of a person

A) 1-4 m / s - positive action

B) >10 m/s – negative action

3) promotes air self-purification

4) a change in the direction of air movement leads to a change in the weather

5) air movement is taken into account when planning settlements for the correct placement of residential and industrial zones.

27. The complex effect of temperature, humidity and air movement on the human body. Ways of heat transfer and their changes in various conditions of human life.

The complex effect of meteorological factors on the body. The physical factors of the external environment act on the human body in a complex way and provide a certain functional state, which is commonly called thermal. When assessing the thermal state of the body, a thermal comfort zone is distinguished - this is a complex of meteorological conditions (temperature, humidity and air mobility), in which a person experiences a pleasant heat sensation (feeling of comfort) and his thermoregulatory system is in a state of physiological rest. In the temperate climate zone, the most comfortable indoor conditions in summer are provided at an air temperature of 22-24 degrees, a relative humidity of 30-45%, and a mobility of 0.1-0.2 m / s. In the cold season - 18-23 degrees, 40-60%, 0.2 m / s.

As a result of physical thermoregulation, the processes of heat transfer change by convection, radiation, evaporation and conduction. Heat transfer by conduction is carried out in contact with cold surfaces; convection - by heating the air adjacent to the body; radiation - infrared radiation to colder surrounding objects, which does not depend on the ambient temperature; evaporation - the release of heat with sweat. In a state of rest and thermal comfort, heat loss by convection is 15.3%, by radiation - 55.6%, and by evaporation - 29.1%. Due to the regulation of the processes of heat generation and heat transfer, a person is able to maintain a constant body temperature with significant fluctuations in air temperature, however, the limits of thermoregulation are not unlimited, and their transition leads to a violation of thermal equilibrium, sometimes with deep pathological changes (overheating or hypothermia). Overheating usually occurs when the ambient temperature is high, combined with high humidity and no air movement. There are two manifestations of overheating: hyperthermia (in severe cases - heat stroke) and convulsive illness, which occurs due to a sharp decrease in chlorides in the blood and tissues released during intense sweating. Hypothermia occurs when a combination of low temperature with high humidity and speed of movement. Hypothermia can be general and local. Thus, high air humidity plays a negative role in thermoregulation, both at high and low temperatures, and an increase in air velocity, as a rule, contributes to heat transfer. The exception is when the air temperature is higher than body temperature, and the relative humidity reaches 100%.

29.. Hygienic characteristics of infrared radiation, measures to prevent adverse effects.

Infrared radiation is radiation, the spectrum of solar radiation of which is a wavelength from 760 to 4000 nm.

The effect of infrared radiation on the human body can be both positive and negative.

Positive effect of infrared radiation:

Surface thermal action

Deep thermal effect (increases metabolism, gas exchange, excretory function of the kidneys, blood flow, has a resolving, anti-inflammatory and analgesic effect)

Negative effect of infrared radiation:

Overheating

Sunstroke

Heatstroke

Erythema

Cataract

Wearing a headdress

Protective glasses

Rational clothing (clothes for the season, light colors, natural fabrics, hygroscopic, breathable, etc.)

The inadmissibility of limiting the use of water

30. Hygienic characteristics of the visible part of the solar spectrum, measures to prevent adverse effects.

Visible radiation - radiation, the spectrum of solar radiation of which is a wavelength from 400 to 760 nm.

Provides the function of the organ of vision

Increases the activity of the cerebral cortex, vitality, affects the functions of all organs and systems

Activates metabolism, immunobiological activity of the body

Retinitis

Myopia

A measure to prevent the adverse effects of the solar spectrum in the room is to ensure optimal natural lighting in the workplace.

31. Hygienic characteristics of ultraviolet radiation, measures to prevent adverse effects in conditions of insufficient and excessive exposure.

Ultraviolet radiation - radiation, the spectrum of solar radiation of which is a wavelength from 200 to 400 nm.

Positive effect on the body:

General biological effect (increases metabolism, production of biologically active substances, hematopoiesis, immunity)

Specific action (pigment formation, antirachitic, bactericidal action)

Negative effect on the body:

Sunstroke, burns in severe cases

photosensitization

Photophthalmia

Skin cancer

Measures to prevent adverse effects:

Proper sunbathing

Protective glasses

Rational clothing

Limiting time spent in the sun

In a hot climate, repeated exposure to conditions that threaten to overheat the body also leads to the development of adaptive changes. They consist in the restructuring of metabolism in the direction of lowering the overall level of heat generation and increasing the efficiency of physical thermoregulation: the basal metabolism is reduced by 10-15%, blood pressure is also reduced, muscle tone is weakened. Sweating - at the same skin temperature and pulse rate - is increased by about one and a half times, and from areas of the body that are exposed to especially strong heating - by 2-3 times. The composition of sweat also changes: the content of sodium chloride in it decreases and the content of substances that lower the surface tension of sweat increases. Due to this, increased sweating is accompanied by relatively less hypochlorite and hyponatriemia, and the sweat released on the surface of the skin does not form drops, but a thin film of moisture spreading over the surface of the skin, which contributes to its better evaporation. A very important role in the process of acclimatization to heat is played by increasing the efficiency (training) of the cardiovascular system. Hyperemia of the skin leads to a decrease in venous flow to the heart and a sharp increase in heart rate with an unchanged or even reduced minute volume of blood. With repeated exposure, the increase in heart rate decreases, the blood supply to the internal organs improves. The changes in the circulatory system occurring in the process of acclimatization to the heat are very similar to those observed during training for heavy muscular work. Therefore, people trained for significant muscle loads are better able to tolerate heat and acclimatize more easily in hot climates. Acclimatization to heat occurs faster if a person is exposed to heat at the same time as doing muscular work (so-called active acclimatization). However, active acclimatization should be carried out carefully, under medical supervision, since this can easily create conditions that exceed the capabilities of the compensatory adaptive systems of the body.

As is known, in conditions of heat, not only thermal disturbances (heat exhaustion, heat stroke), but also water and salt metabolism can occur. But if an increase in the efficiency of the thermoregulatory system during acclimatization can be easily observed after a few days or weeks, then an increase in the efficiency of systems that regulate water-salt metabolism cannot be detected even in desert conditions. There is no evidence that acclimatization to heat can reduce the body's need for water or increase tolerance to dehydration. Artificial restriction of water consumption in a dry hot climate not only does not lead to a decrease in sweating (however, this would only be harmful, since under these conditions the evaporation of moisture is the only physically possible mechanism for heat transfer), but only causes blood to thicken, depleting it of sodium chloride, an even greater decrease in blood pressure, a sharp decrease in diuresis and other changes that further complicate the work of the heart, kidneys and other organs.

The feeling of thirst very often lags behind the actual degree of dehydration of the body. In the presence of a limited supply of water, even in the most heat acclimatized people, deliberately limiting drinking and "saving" water consumption does not provide any benefits in terms of better thermoregulation or increased endurance.

Under such conditions, it may be effective to transfer the working time to the night and early morning hours of the day, when the temperature and especially the thermal radiation of the sun is less than in the daytime.

An increase in heat transfer can be achieved by evaporation of any liquid on the human body, and not necessarily sweat. Therefore, in the conditions of settlements or hot shops, various methods of spraying moisture can play a very important role - water-air showers, fountains spraying water, etc.

In the conditions of settlements, acclimatization to a dry hot climate is easier than to a humid hot one. If in the first case various ways of protecting against solar radiation and increasing the speed of air movement can play a large positive role, then in a hot humid climate, practically the only effective way to meet the physiological needs of the body is to use devices for air conditioning (cooling and dehumidification).

The phenomena of acclimatization to violations of salt metabolism were also not found. Therefore, the most important condition for acclimatization to heat is the fullest possible compensation for the loss of water and sodium chloride (see above).

In the phenomena of acclimatization to heat, an important role is also played by the development of behavioral skills in these conditions, better recognition of signs of a threatening state and their timely prevention. But both in cold and hot conditions, no signs of the possibility of acclimatization by changing the temperature of the deep layers of the body were found. See also Climate.

Tourists who go on vacation to hot countries are very concerned about such an issue as acclimatization. Of course, I want to have a pleasant vacation by the sea and evening walks along the promenade, and not in a hotel room or in a first-aid post. These fears are not unfounded, since not every person can endure a sharp change in climate. This mainly affects people who have chronic diseases (especially the respiratory tract), children and the elderly who find it difficult to adapt. For people who are hard to tolerate acclimatization, the main symptoms are headache, nervous system disorders, weakness of the body, intestinal upset, high blood pressure, rapid pulse, and so on.

It is easier and softer for people to acclimatize in a hotter and drier climate, the reason for this is sweating. Sweating in this case works like an air conditioner. Sweat, evaporating, cools the surface of the skin, thus maintaining the desired temperature for the body. But in a hot climate, there is such an irritant as dust, which rises into the air from the breath of the wind, cars, people walking and other things, but you can quickly get used to it.

In countries where high air humidity is combined with high temperatures, acclimatization is difficult. Sweating does not help much here, because sweat cannot evaporate quickly, which is why the temperature regime of the body is disturbed. Under such conditions, a person's pulse quickens, the body gradually overheats, blood flow to the internal organs decreases, which causes rapid breathing, a feeling of constant thirst.

Symptoms.

In the process of acclimatization, the symptoms that arose at the beginning gradually disappear, as the body tries to adjust itself to certain conditions. For most people, they go away completely, but there are those who still cannot completely get rid of them. The most dangerous climatic conditions are considered to be a humid climate with high temperatures. Under these conditions, a person's condition can greatly deteriorate up to hospitalization. These can be heat cramps, which occur due to the loss of mineral salts by the body, heat strokes, which are caused by a large loss of moisture by the body and its overheating.

Treatment.

All these ailments can be prevented by preventive actions, such as water regime, food intake, rest. For example, drinking plenty of water is not recommended, water should be drunk in small sips in a limited amount (with the exception of only after eating). It is desirable to take food only in the morning and in the evening in order not to overload the body during the day. Clothes for hot places should be chosen spacious and be sure to wear a hat, which will help to avoid heat stroke. It is advisable to take a cool shower several times a day and rest as often as possible, especially during the day, as well as ventilate the premises. In order to avoid unforeseen circumstances, it is recommended to take a first aid kit with you on the road. In the first aid kit, there must be antipyretic drugs, such as aspirin, paracetamol, ibuprofen, as well as drugs for hepatitis and SARS common in resorts, such as lavomax, ointments for burns, vitamins if there are children on the trip.