Viral infections cause upper respiratory tract infections, and fever usually lasts for about 1 week before gradually subsiding. Viral infections are a common type of infection in pediatric patients, and 90% of all upper respiratory tract infections are due to viral infections. Depending on the site of infection, viral infections can cause different clinical manifestations, such as fever, cough, sputum, headache, nausea, diarrhea, and localized skin lesions. The duration of fever varies depending on the site of infection. Fever caused by viral infections such as influenza virus, enterovirus and herpes simplex virus usually lasts for about 1 week to gradually subside. Fever caused by viral infections such as EBV can last for 2 weeks or longer, and viral encephalitis may also last longer. Therefore, for viral infections, the duration of fever varies with different viruses and different sites of infection. Pediatric fever should be treated aggressively. If the child’s body temperature does not exceed 38.5°C, physical cooling can be taken; if the body temperature exceeds 38.5°C, antipyretic drugs need to be given.