Newborn infants’ body temperature is not fixed and can fluctuate with the surrounding environment, day and night, activities, emotional changes, dietary intake and other factors, but is often within the normal range, and the general situation of infants and children’s body temperature measurement site is different, the body temperature also fluctuates slightly. The normal body temperature is between 36.5℃ and 37.5℃ at the anus, 36.2℃ and 37.3℃ at the mouth, and 35.9℃ and 37.2℃ at the armpit. If the body temperature exceeds the normal range by more than 0.5℃, it is considered fever, not more than 38.2℃ is called hypothermia, and more than 39.2℃ is considered hyperthermia. There are many causes of fever, including infectious fever and non-infectious fever, and the treatment of different causes is different and requires symptomatic treatment. Infants and children with high fever need emergency cooling and rehydration treatment to prevent febrile convulsions, generally using physical cooling such as warm towels on the forehead, alcohol baths, ice packs to assist in cooling, in addition to the need to cooperate with drugs such as ibuprofen suspension orally, if necessary, hormones and other symptomatic treatment (specific medication, please combine with clinical, subject to the guidance of the doctor’s interview). Secondly, the ambient temperature and ventilation should be changed. On the other hand, laboratory tests such as routine blood tests and viral tests should be performed. Therefore, if fever occurs, there are many reasons for it, so we should treat it with the symptoms, and if necessary, conduct relevant tests to clarify the diagnosis and treatment.