From the perspective of human physiological structure, because the blood circulation of the nasal mucosa is very strong, the passage in the nasal cavity is very tortuous, and the nose hair constitutes a filtering "barrier". When air is sucked into the nostril, the airflow forms a vortex in the tortuous passage, which warms the airflow sucked into the nasal cavity.
Some tests have shown that when cold air of minus 7°C is sucked into the lungs through the nose, the airflow has been heated to 28.8°C, which is very close to the temperature of the human body. If you wear a mask for a long time, the nasal mucosa will become fragile and lose the original physiological function of the nasal cavity, so you cannot wear a mask for a long time. Masks can only be worn in special environments, such as places with many people and poor air circulation.
Of course, to walk in the wild, in order to resist wind, sand and cold, or activities in an environment with air pollution, you need to wear a mask, but the time should not be too long. In addition, in the flu season, you should wear a mask when you go to public places where there may be a large number of pathogens. Wearing a mask is just one of the ways to prevent respiratory infectious diseases, and the most important thing is to maintain good living habits.
