The normal value of measuring body temperature depends on the measuring part of the body temperature, and it is generally appropriate to measure the oral cavity, axilla, rectum and other parts for the main. The normal value of sublingual temperature is between 36.3-37.2℃, the normal value of rectal temperature is between 36.5-37.7℃, axillary temperature is between 36.0-37.0℃, greater than the high limit can be designated as fever. Below 38.0°C is low fever, 38.0-39.0°C is designated as moderate fever, above 39.0°C as high fever, and above 41.0°C as ultra-high fever. This temperature classification is based on the sublingual and axillary temperatures, and the human body, which is relatively little affected by the external environment, does not exceed 1°C at most.