Khankeldiev Sh. Kh. Regional features of the physical status of youth students fergana 2022 Reviewer

1.4. MEASUREMENT AND EVALUATION OF TEMPERATURE CONDITIONS
S ince heat transfer from the body to the environment occurs due to various mechanisms, and each of them is determined by various environmental factors (for example, the evaporation rate depends on air humidity, and the direct transfer of heat does not depend on this indicator, the degree of heat load experienced by a person depends not only on the ambient temperature, but also on a number of other characteristics, such as air humidity, wind speed, ambient temperature, degree of protection from solar radiation, etc. Therefore, several main indicators are used to characterize external temperature conditions. In particular, estimates of air humidity use dry and wet bulb readings, which do not differ at 100% air vapor pressure (relative humidity).

Rice. 1. Effective temperature scale for comfort zones for various regions of the globe: I - Iran (upper limit of the comfort zone); Z - Singapore; 3 - Kolkata; 4 - USA, summer (optimal comfort zone); .5 - USA, winter and summer (optimal comfort zone); b - England, summer (optimal comfort zone), in order to determine the effective temperature, you should connect the points on the vertical tear scale and on the right with a straight line, respectively, to the measured values, and then find the point of intersection of this straight line with the grid line that determines the speed air movement

An isolated definition of the above-mentioned indicators of temperature regimes is summarized in terms of the so-called effective temperature, which is based on data on subjective feelings of a person, active temperature as a certain integral indicator makes it possible to characterize the combined effect of temperature, humidity and air velocity. To offset the effective temperature, it is necessary to identify the values ​​on the vertical scales on the left in a straight line on the given nomogram and thus find the point of intersection of this line with the same grid, which corresponds to the air velocity.
The effective temperature is estimated in this case on an inclined scale, the left vertical scale characterizes the data of a dry thermometer, and the right one characterizes a wet one. On fig. the boundaries of thermal comfort zones" for various regions of the globe are also given.
If you are in your comfort zone, doing moderate physical work does not pose a health risk. If the human body is affected by high air temperature in combination with high humidity, then this combination of conditions can be dangerous.
If about 75% of the sweat glands are activated, the subject evaluates this condition with the word "hot". With the activation of 100% of the sweat glands, the situation is rated as "very hot" and are largely dependent on each other, then of course there is a certain relationship between the core body temperature and active sensations. The intensity of physical activity at high air temperature
Can be classified:
| - light (up to 38.1°С);
| - difficult (38.1-39.4°C);
| - excessively difficult (more than 39.4 ° C).