The optimal temperature for the human body is around 25 degrees, but the human body’s degree of adaptation to temperature varies according to different parts of the body, different ages, and external temperature conditions. Different parts of the human body have different comfortable temperatures, and the temperature gets higher as you move inward, for example, the hands, feet, and limbs have lower temperatures, and the abdomen and other parts of the body have higher temperatures. The metabolic capacity of young people is metabolically active, so the comfort temperature of young people is lower than that of the elderly. The comfort temperature of women is higher than that of men. The temperature of the surrounding environment has a significant influence on the human body’s comfortable temperature, for example, the human body’s comfortable temperature is 19 to 24℃ in summer, and about 17 to 22℃ in winter.