Humid air at any temperature is not good for the human body.
Research has shown that when the temperature is too high, the amount of pineal hormone secreted by the pineal gland in the human body is also large, making the concentration of thyroxine and adrenaline in the body is relatively low, the cells will be "lazy", people will be lethargic, depressed. Long time in the humidity of the place of work, life, but also prone to dampness paralysis; humidity is too small, evaporation accelerated, dry air is easy to take away the human body's moisture, so that the skin is dry, the mucous membranes of the nasal cavity is stimulated, so in the fall and winter dry and cold air invasion, very easy to induce respiratory diseases. In addition, air humidity is too large or too small, are conducive to the reproduction and spread of some bacteria and viruses. Scientific determination, when the air humidity is higher than 65% or lower than 38%, the germs reproduce and breed the fastest, when the relative humidity is 45%-55%, the germs die faster.
Relative humidity is usually associated with air temperature and air pressure*** with the role of the human body. Modern medical meteorological research shows that the human body is more suitable for the relative humidity: summer room temperature of 25 ℃, the relative humidity control in 40% -50% more comfortable; winter room temperature of 18 ℃, the relative humidity control in 60% -70%. In summer, three volts, due to high temperature, low pressure, high humidity, the human body sweat is not easy to discharge, sweating is not easy to be evaporated, and thus will make people irritable, fatigue, loss of appetite; winter humidity is sometimes too small, the air is too dry, easy to cause mucous membrane infection of the upper respiratory tract, suffering from colds. According to scientific experiments, in the temperature inter-day change of more than 3 ℃, air pressure inter-day change of more than 10 hPa, relative humidity inter-day change of more than 10%, the incidence of arthritis will increase significantly.
The high-temperature indicator of human lethality also has a strong relationship with air humidity. When the temperature and humidity up to a certain limit, the body's heat can not be emitted, the body temperature will rise, so that more than the body's heat limit, people will die. Therefore, China's provisions for catastrophic weather standards, south of the Yangtze River, the highest temperature is higher than 38 ℃, or the highest temperature of 35 ℃, while the relative humidity is higher than 61%; north of the Yangtze River, the highest temperature of 35 ℃, or the highest temperature of 30 ℃, while the relative humidity is higher than 64%.
Summer, humidity increases, the water vapor tends to be saturated, will inhibit the body's ability to play the function of heat dissipation, making people feel very hot and irritable. In winter, when humidity increases, it accelerates heat transfer by about 20 times, making people feel more chilly and depressed. Arthritis patients, due to damage to the synovial membrane of the joints and surrounding tissues in the diseased area, have a weakened ability to resist external stimuli, and are unable to adapt to the intense cooling, which aggravates their condition or increases their aches and pains. If the humidity is too small, due to the mucous membrane of the upper respiratory tract a large loss of water, people feel dry mouth, and even sore throat, hoarseness and nosebleeds, and induced colds. Research also shows that when the relative humidity of 90% or more, 26 ℃ will make people feel like 31 ℃. Dry air absorbs sweat at a rate equal to that of human sweat glands, making us feel cooler. However, the humidity of the air has long been full of moisture, and therefore unable to absorb moisture, so sweat only to accumulate in our skin, so that our body temperature continues to rise, while the heart is not overloaded