If a child’s fever temporarily subsides after taking antipyretic medication, but then rises again after a few hours, the main reason is that the infection is not under control. Because the fever is a symptom, the underlying cause is the infection, and until the infection is controlled, the fever will come back again and again. In general, if the child has a mild viral infection, the fever will often subside within 3 days. However, if the infection is not completely controlled within 3 days, the fever may come back again and again. Sometimes the fever will come back 3-4 hours after the child takes the antipyretic medicine, but in general, the interval between fevers will gradually increase. In addition, the highest temperature of the fever, the fever peak, will gradually decrease, indicating that the child’s fever is slowly improving. However, another reason is to find the cause of the fever, because the infection is more serious and not completely controlled, so timely anti-infection treatment should be carried out to fundamentally solve the situation of recurrent fever in children.