Once a person has a high fever of 40°C for more than about 3 days, the body will produce a series of serious adverse reactions. For children, a high fever of 42℃ or more can easily lead to neurological damage in children. Body temperature over 39℃ is called hyperthermia, and the body is in a high metabolic state when it exceeds 40℃, and the heart rate and heart rate are very fast, which can induce acute cardiovascular and cerebrovascular events to occur at this time. After the hyperthermia lasts for a period of time, there is a serious loss of body fluid, and the patient will have symptoms such as hypovolemic shock, convulsions, delirium and confusion. At this time, rehydration measures should be taken immediately, while physical cooling can also be taken at home, i.e., using ice packs, cold towels on the patient’s forehead, armpits or wiping the whole body. In addition, if a child has a high fever of 40°C or higher, the central nervous system is easily damaged and should be taken to the hospital immediately. During the recovery period, patients should take rest, eat a light diet, and avoid eating foods that are too oily.