High fever is also known as hyperthermia, body temperature greater than 39 ° C is called hyperthermia, greater than 41 ° C is called ultra-high fever. High fever, on the one hand, to use a variety of ways to reduce fever: physical cooling available cold towels, ice packs, chemical refrigeration bags, such as local cooling, but also warm water baths, alcohol baths to reduce the body temperature; can also be used to reduce the temperature of medication, such as oral ibuprofen or acetaminophen, intravenous aspirin or anus inserted into the antipyretic pessary, or even the application of glucocorticosteroids, such as dexamethasone, etc. to reduce the temperature. On the other hand, it is more important to identify the cause of hyperthermia by taking a medical history, physical examination by a doctor, laboratory tests such as blood, urine and feces, as well as ultrasound or imaging tests such as X-rays and CT. That is to say, symptomatic treatment of high fever at the same time to identify the cause of the disease, identify the cause of the disease and then target the cause of the treatment is the key to the success of the treatment. The causes of fever are categorized into infectious and non-infectious. Infectious fever refers to fever caused by pathogens such as bacteria, viruses, fungi, mycoplasma, chlamydia, parasites and other pathogens that infect the body. If it is an infectious fever, it should be actively anti-infectious treatment. If it is not infectious fever, it should be treated according to different causes.