When the weather is muggy, people feel uncomfortable, usually for the following reasons: 1. Insufficient ventilation and oxygenation capacity when the weather is excessively muggy, resulting in a lack of oxygen in the body, and when the human brain is hypoxic, the ratio of ventilation and blood flow will be imbalanced due to low arterial oxygen saturation, high partial pressure of carbon dioxide, and insufficient oxygen content, at which time the body will feel weak and uncomfortable. 2. It is because when the weather is too hot, the blood viscosity and blood stickiness will increase, which will lead to the appearance of clinical symptoms such as weakness, drowsiness and discomfort. 3, the hot weather will cause the onset of coronary heart disease and unstable angina, which is caused by insufficient blood supply to the heart in the case of coronary atherosclerotic heart disease. 4, the hot weather will lead to the precursor of heat stroke, when the body will feel weak and uncomfortable. 5, the hot weather will lead to the precursor of heat stroke. 5, when the weather is hot, people will sweat excessively, with sweat will have excessive sodium and chloride ion loss, ion disorders will also lead to discomfort around the body.