Determining whether a fever is low, i.e. hypothermia, needs to be classified according to different methods of measurement. In adults, a temperature of 36.9°C falls within the normal range for axillary, oral and anal measurements. The range of normal body temperature varies among different methods of temperature measurement, such as 36-37℃ in axillary method, 36.6-37.2℃ in oral method and 36.5-37.7℃ in anal method. In clinical practice, oral temperature is usually used as a criterion to classify the degree of fever. Low fever is 37.3-38℃, moderate fever is 38.1-39℃, high fever is 39.1-41℃, and ultra-high fever is above 41℃. If the self-test temperature is abnormal in daily life, it is recommended to go to a regular hospital to avoid delaying the condition.