The normal body temperature of infants 0-6 months is between 36.3℃-37.3℃ in the axillary temperature of the mercury gauge, with slight individual differences. The normal body temperature of infants is between 36.3℃-37.3℃ in the axillary temperature of mercury thermometer, but some infants may be lower or a little higher, and need to be combined with the usual basal body temperature to make a comprehensive judgment. It takes 10 minutes to measure the temperature under the armpit. When the axillary temperature exceeds 37.3℃ but is around 38℃, this is in the hypothermia range. And when the body temperature exceeds 38℃ and is around 39℃ then it belongs to moderate fever. When the body temperature exceeds 39°C, it is high fever. Once the body temperature exceeds 41°C, it is classified as ultra-high fever, which is a medical crisis and requires urgent medical attention. There are many causes of fever in infants, it is recommended to go to the hospital in time, complete the examination to clarify the cause of the disease, and then give targeted treatment.