Persistent fever of 39°C requires prompt application of antipyretic drugs to reduce fever, as failure to do so can cause damage to the body’s nervous system. Especially in pediatric patients, persistent high fever may lead to febrile convulsions. When the body temperature is at 39℃, antipyretic drugs such as acetaminophen, compound zinc-cloth granules, ibuprofen, etc. need to be applied. If oral antipyretic drugs are not effective, intramuscular or intravenous antipyretic drugs can be chosen, or anal suppository medication can be performed. If the body temperature does not drop 4 hours after medication, then it is necessary to be admitted to the hospital for some blood tests to clarify the causative source of the fever. If, in addition to fever, the patient has a cough, sputum, or even wheezing, a chest X-ray or CT scan can be taken to understand the lung condition and exclude acute pneumonia. For some bacterial infectious diseases, such as pneumonia, lung abscess, purulent tonsillitis, urinary tract infection and intestinal infection, anti-inflammatory treatment with antibacterial agents should be applied, and the high fever can be controlled only after the inflammation is eliminated. Besides, there are also some severe stages of cardiovascular and cerebrovascular diseases, and the symptoms of persistent hyperthermia can also occur. Therefore, patients with persistent hyperthermia must visit a doctor to identify the cause of fever and treat it systematically.