36.9°C is not considered a fever, it is a normal body temperature. Generally normal body temperature is not a specific temperature point, but a temperature range. The deep body temperature of the organism is more constant and uniform, called deep body temperature; while the surface temperature of the body is affected by a variety of factors and varies and varies widely, called superficial temperature. The body temperature referred to clinically is the average deep temperature, which is generally represented by the body temperature of the oral cavity, rectum and axilla. Its normal value is 36.3℃-37.2℃ for oral sublingual temperature, 36.5℃-37.7℃ for rectal temperature, and 36.0℃-37.0℃ for axillary temperature. Regardless of the measurement method, 36.9°C is the normal body temperature. If the measurement site is the armpit, wipe the armpit clean if necessary and remeasure the temperature for no less than 5 minutes. It is recommended that you should pay attention to diet and nutrition, prevent cold and keep warm, do not stay up late, pay attention to rest, actively participate in physical exercise, and abstain from smoking and alcohol as well as spicy and stimulating diet.