The normal axillary measurement of body temperature in adults is 36 to 37 degrees Celsius. Normal body temperature is usually obtained by measuring the armpit temperature. Adult armpit temperature is usually 36~37 degrees Celsius, more than 37.2 degrees Celsius is regarded as fever. 37.3~38 degrees Celsius is regarded as low fever, 38~39 degrees Celsius is regarded as moderate fever. 39 degrees Celsius or above is regarded as high fever. In addition to axillary temperature, there are other methods of measuring body temperature, such as anal temperature. This method is used for comatose and tracheotomized patients and infants. Anal temperature, also known as rectal temperature, is closest to the body’s core temperature. Anal temperature is 0.5 to 0.7°C higher than axillary temperature. Normal anal temperature is between 36.5 and 37.7°C. Fever is one of the more common clinical symptoms, its causes are also more, differential diagnosis is complex, need to combine with the history, clinical manifestations and a number of auxiliary examination and other comprehensive analysis.