Fever is a common symptom in children, mostly seen in respiratory tract infections. Fever is a defensive response of the body, which helps to destroy germs in the body. However, children feel uncomfortable during high fever, which can cause seizures in severe cases. The World Health Organization recommends that when the axillary temperature is 38.5°C and is accompanied by irritability, the child should be given prompt fever relief treatment. If a child under 5 years old has a history of fever and seizures, or if the child has pneumonia, heart failure, myocarditis, or congenital heart disease, antipyretic treatment should be given even if the fever is less than 38.5℃. Infants under half a year old with fever should not use antipyretic drugs to lower their body temperature, but should use physical cooling, such as loosening the wrap and taking a warm bath. Non-pharmacological treatment: The first choice is to drink more water, wear less clothes or cover less, and lower the room temperature to about 25℃ in summer. Drug antipyretic: oral antipyretic drugs: the World Health Organization advocates oral antipyretic drugs. When the child refuses to take oral medication, fever suppositories can be used to plug the anus, absorbed by the intestines, the effect of fever reduction is rapid. At the same time, drink more boiled water and pay close attention to changes in the condition. Intramuscular injection: At present, the injections used to reduce fever in children are mainly aminopyrine and its derivatives, such as: analgin, anandamide, etc. (containing aminopyrine ingredients), these drugs have large side effects, easy to produce deficiency or even shock, but also allergic rash (urticaria, exudative erythema, exfoliative dermatitis), more serious can cause granulocytopenia, aplastic anemia. In addition, these drugs are injected intramuscularly with greater local irritation, which may cause hip muscle damage resulting in complications such as hip muscle atrophy, paralysis and infection. Antipyretic drug dosage forms: there are four kinds of water, tablets, suppositories and injections. The efficacy of antipyretics in descending order are: ibuprofen, acetaminophen, compound aminopyrine and aspirin. Dosage and safety of commonly used antipyretics: Ibuprofen (Torn, Merlin): orally, 5-10 mg/kg body weight each time, at 6-8 hour intervals if necessary. It can be used in children over 6 months of age and has no effect on the hematopoietic system and is safe. Acetaminophen a.k.a. Paracetamol (Tylenol, Benadryl): Oral, 10-15mg/kg body weight per dose, at 4-6 hourly intervals if necessary. It can be used for more than 2 months, has no effect on the hematopoietic system and is safe. Aspirin also known as acetylsalicylic acid: Aspirin is clearly prohibited and unsafe for children under 16 years old in the UK. Compound aminopyrine (Advil): intramuscular injection, unsafe, can induce acute hemolytic anemia, rash, prohibited in infants and children, and used with caution in older children. Lysampyrine: It is a product of aspirin combined with lysine and is generally safe. It can be injected intravenously or intramuscularly. Compounded aspirin (APC): Generally not recommended, especially for children under 3 years of age, inducing convulsions and causing a decrease in white blood cells and platelets. Anacin: can be used 20% solution for nasal drops, intramuscular injection, unsafe. Prohibited or restricted use, can cause granulocytopenia. Nimesulide (Riziqing): On May 20, 2011, the State Food and Drug Administration issued a notice amending the instructions of Nimesulide to prohibit the use of the oral formulation in children under 12 years of age.