Fever in children is a self-protective mechanism to fight against the disease by mobilizing the whole body’s immune system. Body temperature is closely related to the child’s physical condition, nutritional status, time (such as morning and evening, seasons), but not related to the severity of the disease, i.e., it is not the higher the temperature, the more serious the disease, and sometimes repeated high fever for 3-5 days is very common, so in the process of antipyretic, we should actively look for the treatment of the primary pathology, and do not simply focus on antipyretic. I. When to apply antipyretics? Axillary more than 37.3°C is defined as fever. It is further divided into low fever 37.4~38°C; medium fever 38.1~39°C; high fever 39.1~41°C; and ultra-high fever: above 41°C. Fever of ≤1 week is considered acute fever. For patients with temperature below 38.5°C, if the mental state is good, antipyretics can be withheld and physical cooling is sufficient. For patients over 38.5°C, antipyretic drugs should be applied to reduce energy consumption and avoid complications such as febrile convulsions. The World Health Organization (WHO) recommends two classic oral antipyretics that are safe for pediatric use: acetaminophen and ibuprofen. For recurrent high fever, the two can be used alternately; Nimesulide is prohibited for children under 12 years old. Third, the application of clinical pediatric antipyretic principles Infants less than 3 months old are not recommended to use antipyretic drugs, can use physical cooling to reduce fever. When the body temperature is lower than 38.5 ℃, generally do not use antipyretic drugs, can be used to physical cooling methods to reduce fever, except for repeated episodes of febrile convulsions. When the body temperature is higher than 38.5 ℃, safe antipyretic drugs can be used to treat, should avoid rapid fever, and alert to possible dehydration, if necessary, intravenous rehydration. Ultra-high fever (>41 ℃), will cause permanent damage to brain cells, and even other serious complications, such as pulmonary edema, cerebral edema, liver failure, etc., serious cases can lead to death, so active and effective rescue measures should be used to rapidly reduce the temperature. Children with persistent high fever, if the single drug is not good, can be alternately applied acetaminophen and ibuprofen. Alternate between the two drugs at least 2 hours apart. When alternating, the maximum number of times each medicine can be used remains 4 times a day. Drink plenty of fluids when taking medication to reduce fever, to speed up excretion and help take away heat from the body. At the same time, taking medication to lower the temperature at the same time also need to cooperate with physical means of lowering the temperature, which includes taking a warm bath, or wet hot towels to wipe the whole body, do not use alcohol to wipe, alcohol is easy to pass through the tender skin of children lead to alcohol poisoning. Avoid multiple antipyretic drugs used at the same time, increasing the risk of side effects. Fourth, the application of pediatric antipyretic drugs should pay attention to matters (1) pediatric thermoregulation center is not perfect, so pediatric fever should be based on physical cooling. (2) Fever is the body’s resistance to disease manifestation, should actively find the cause, treatment of primary diseases. (3) Master the active ingredients of various antipyretic and analgesic drugs, characteristics of drug action, adverse reactions, contraindications, contraindications, etc., to prevent damage to the body due to improper use of drugs. (4) According to the characteristics of pediatric antipyretic drugs, reasonable control of pediatric antipyretic use interval. (5) should be taken on time and in accordance with the amount, do not arbitrarily increase the dose or shorten the dosing interval. (6) During the period of antipyretic, children should be asked to drink more water, so as not to cause dehydration due to profuse sweating. (7) Generally, one antipyretic should be used, and a combination should be considered when the efficacy is really unsatisfactory. Check the temperature about one hour after each dose to determine the effect of antipyretic. (8) Reasonable mastery of the use of treatment, fever, stop. (9) During the use of drugs should pay attention to the toxic side effects of drugs, such as blood changes, gastrointestinal reactions, liver and kidney function impairment. (10) Severe, high fever persists in children, if necessary, can choose subhibernation therapy.