With the onset of summer, fevers in children are gradually increasing. Fever, commonly known as fever, is the most common symptom of childhood illness. Generally, a fever in children is indicated by an anal temperature of 37.8°C or higher, an oral temperature of 37.5°C or higher, and an axillary temperature of 37°C or higher. The most common causes of fever in children are infectious diseases, the most common of which are respiratory infections, such as tonsillitis, upper respiratory tract infections, bronchitis, and pneumonia. Other causes of fever are in the minority. A simple way to determine whether the fever is viral or bacterial in origin is to check the blood routine and, if available, the C-reactive protein at the same time. The correct way to judge the blood routine is that if there is an abnormality in the blood routine, it means there is a significance; if the blood routine is within the normal range, it does not mean there is no problem. Generally speaking, a high WBC indicates a heavy inflammatory response; an elevated neutrophil ratio indicates a high possibility of bacterial infection; if the WBC is low, especially below normal, it indicates a high possibility of viral infection. In children with fever, generally speaking, the first choice of antipyretic medicine is ibuprofen suspension, which is often used when the fever is high, usually when the anal temperature reaches 38.8℃ or more or the oral temperature reaches 38.5℃ or more or the axillary temperature reaches 38℃ or more (try not to use axillary temperature because it is less accurate). Regardless of low or high temperature, you can use antipyretic paste or ice treasure paste during the day, and cold water towel on the head and forehead at night; before going to bed at night, you can use a hot bath. In addition, according to my personal experience, in hot weather, using air conditioning is better than using electric fans blowing directly, but the air conditioning temperature must be adjusted slightly higher, in addition, the room to maintain a certain level of humidity. When you have a fever, try not to eat cold food or cold fruits, such as sour milk, watermelon, bananas, and drink warm plain water. Also, to clarify: use antipyretic drugs cautiously for small infants under 3 months of age; if necessary, try to perform physical cooling as described above, such as loosening the bag.