Normal body temperature is a range that generally involves three parts of the body when it comes to body temperature, axillary, oral, and anal. The normal range of axillary temperature is 36.0°C-37.0°C; the normal temperature of oral temperature is only 36.3°C-37.2°C; the normal temperature of anal temperature is 36.5°C-37.7°C. Generally speaking, body temperature is not fixed and can fluctuate normally with age, day and night, gender and emotion. Newborns have imperfect thermoregulation and are susceptible to environmental temperature, while children have a slightly higher body temperature than adults due to an increased metabolic rate. Older adults have a body temperature at the low end of the normal range due to a lower metabolic rate. In general, normal people have the lowest body temperature in the early morning at 2-6 am and the highest body temperature at 2-8 pm, but the fluctuation range is not more than about 1℃. Generally speaking, women have a slightly higher body temperature than men. Exercise, bathing, eating, and mental stress can cause a temporary increase in body temperature. Quietness, sleep, hunger, and taking sedative drugs can all cause the body temperature to drop temporarily.