A high fever is generally defined as a body temperature of 39.1°C or higher (as measured by axillary temperature) and is a response of the body to pathogenic factors. A common sequela of high fever is dehydration. Because high fever itself causes a large amount of dehydration in the organism, coupled with a large amount of sweating after using some antipyretic drugs, patients may suffer from thirst and even irritability and hyponatremia as a result. The next is febrile convulsions and secondary epilepsy. Generally brief convulsions are not too damaging to the brain, but repeated febrile convulsions can damage brain cells and can cause mental retardation. Repeated hyperthermia, especially when the body temperature is greater than 40°C, can cause brain damage and even cerebral edema, leading to serious sequelae and even life-threatening. For pediatric patients, if said high fever persists and causes tachycardia, it may also lead to heart failure. When high fever occurs, the first thing to do is to take physical cooling, if it does not work, you should promptly take antipyretic drugs, such as the commonly used acetaminophen, or ibuprofen, the specific dosage, should be combined with clinical, under the guidance of a physician medication. If the effect of oral medication is not good, it is best to go to the hospital in a timely manner, improve the relevant examination, identify the cause, and then the symptomatic treatment.