Fever should be reduced according to the degree of temperature increase to choose the appropriate method of fever reduction. If the body temperature does not exceed 38.5℃, physical cooling can be performed, such as wiping the armpits, neck and upper limbs with alcohol, or using a fever reducing patch. If the body temperature exceeds 38.5℃, oral medication can be used to lower the temperature, such as oral acetaminophen or ibuprofen. Clinically, fever is most commonly associated with infectious diseases, such as bacterial, viral, fungal, mycoplasma, chlamydia, rickettsia, and other pathogenic infections. Clinically, fever can be basically controlled by drawing blood tests (routine blood, C-reactive protein, Chlamydia pneumoniae, virus test) and bacterial culture to identify the pathogens and then treating the etiology for the different pathogens. For example, bacterial infections can be treated with sensitive antibiotics, and some respiratory diseases, such as pneumonia, lung abscess and abscess chest, require a combination of antibiotics. Patients with tuberculosis (e.g., pulmonary tuberculosis, intestinal tuberculosis, etc.) often present with afternoon hypothermia with hot flashes and night sweats, and require anti-tuberculosis treatment for about 2 weeks before their body temperature can return to normal. Etiological treatment is also required for fever caused by malignant tumors, rheumatic immune diseases and infectious diseases. For patients with fever, it is not recommended to go for immediate fever reduction. Blind use of antipyretic drugs may mask the condition on the one hand, and on the other hand, the drugs may team up with liver and kidney to cause damage, so it is recommended to use physical cooling until the cause is identified.