Sweating a lot in summer, which is called "draining" by Chinese medicine, that is, the skin pores are open; On the other hand, in summer, the yang is abundant, and the yang in the body is relatively weak, and the ability to be lower than the exogenous evil decreases. In this case, the evil of cold and dampness is more likely to invade the human body and harm the skin, gastrointestinal tract and muscles. In addition, it is in an air-conditioned environment for a long time in summer, and the temperature is lower than 26℃. In addition, the clothes are thin, revealing shoulders, umbilicus, waist and knees; The temperature difference between indoor and outdoor is large, and there is no transition from high temperature to low temperature, or after sweating, you can take a shower with cold water and blow it with a big fan, which is called "sweating when the wind blows" in Chinese medicine. Excessive consumption of iced, frozen cold drinks and fruits; Some people like to enjoy the cool outside at night and sleep on the cold concrete floor, 86tcm. And so on. These are all opportunities that are vulnerable to cold and dampness.