For a normal adult, the basal body temperature is 36.0-37.3°C. Taking the axillary body temperature as an example, the above body temperature is the basal body temperature, which is also the normal standard body temperature. In mild fever, the body temperature is 37.4-38℃, in moderate fever, the body temperature is 38.1-39℃, in high fever, the body temperature is 39.1-41℃, and in super high fever, the body temperature is greater than 41℃. Therefore, the basal body temperature is the body temperature measured in the resting state when the basal metabolic rate is more normal and balanced, but the body’s basal body temperature is also affected by the circadian rhythm and the temperature difference between indoor and outdoor. The basal body temperature is usually lower in the early morning and higher in the afternoon and late afternoon.