The temperature is 36 degrees, and the outdoor weather is lower than the temperature. Why do people still feel hot?

Humid air is harmful to human body at any temperature.

Studies have shown that when the humidity is too high, the amount of pineal hormone secreted by the pineal gland in the human body is also large, which makes the concentration of thyroxine and adrenaline in the body relatively low, cells will be "lazy", and people will be listless and depressed. Working and living in a place with high humidity for a long time is also prone to dampness; If the humidity is too small, evaporation will be accelerated, and dry air will easily take away water from the human body, making the skin dry and the nasal mucosa stimulated. Therefore, when dry cold air invades in autumn and winter, it is easy to induce respiratory diseases. In addition, too much or too little air humidity is conducive to the reproduction and spread of some bacteria and viruses. Scientifically speaking, when the air humidity is higher than 65% or lower than 38%, the germs multiply fastest, and when the relative humidity is 45%-55%, the germs die faster.

Relative humidity usually acts on human body together with air temperature and air pressure. Modern medical meteorological research shows that the suitable relative humidity of human body is: when the room temperature is 25℃ in summer, it is more comfortable to control the relative humidity at 40%-50%; When the room temperature is 65438 08℃ in winter, the relative humidity is controlled at 60%-70%. In the dog days of summer, due to the effect of high temperature, low pressure and high humidity, sweat is not easy to be discharged and evaporated after sweating, which will make people fidgety, tired and lose appetite. Sometimes the humidity is too low and the air is too dry in winter, which is easy to cause upper respiratory tract mucosal infection and cold. According to scientific experiments, when the daily variation of temperature is greater than 3℃, air pressure is greater than 10 hectopascal, and relative humidity is greater than 10%, the incidence of arthritis will increase significantly.

The high temperature index of human death is also closely related to air humidity. When the temperature and humidity reach a certain limit, the human body's heat will not be emitted, and the body temperature will rise, so that people will die if they exceed the heat resistance limit of the human body. Therefore, the standard of disastrous weather in China is that the highest temperature in the south of the Yangtze River is higher than 38℃, or the highest temperature reaches 35℃, and the relative humidity is higher than 61%; The highest temperature in the area north of the Yangtze River reaches 35℃, or 30℃, and the relative humidity is higher than 64%.

In summer, when the humidity increases and the water vapor tends to be saturated, it will inhibit the heat dissipation function of the human body and make people feel very stuffy and irritable. In winter, when the humidity increases, the heat conduction will be accelerated by about 20 times, which makes people feel colder and more depressed. Arthritis patients' ability to resist external stimuli is weakened due to the injury of synovium and surrounding tissues in the affected area, and they can't adapt to severe cooling, which makes their condition worse or sore. If the humidity is too low, people will feel thirsty because of a large amount of water loss in the upper respiratory mucosa, and even have a sore throat, hoarse voice and nosebleeds, which will induce a cold. The investigation also shows that when the relative humidity is above 90%, 26℃ will make people feel like 3 1℃. Dry air absorbs sweat at the same speed as human sweat glands produce sweat, which makes us feel cool. However, the air with high humidity is full of water and can no longer absorb water, so sweat has to accumulate on our skin, which makes our body temperature rise continuously and our heart overwhelmed.