If a 9-month-old baby suddenly develops a fever, you should determine what the child’s specific body temperature is. If the measured temperature is below 38.5℃, physical cooling can be given. The method of physical cooling is to continuously wipe the child’s neck, underarms, thigh roots and other parts rich in blood vessels with warm water, while wiping, attention should also be paid to heat preservation, and the child should also be given water in small amounts and several times during physical cooling, and the child’s mental changes should be observed. If the temperature drops after physical cooling, you can continue to observe. If the temperature rises and exceeds 38.5℃, oral antipyretic medication, such as ibuprofen, is needed, along with physical cooling. While reducing the fever, pay attention to the cause of the child’s fever. For infants, common causes of fever include respiratory tract infections and digestive tract infections, etc., and give the appropriate medication after determining the disease suffered.