Most fevers are caused by microbial infections and require antiviral or anti-inflammatory treatment along with fever reduction. If you simply take antipyretic drugs, it will not solve the problem at the root, it can only treat the symptoms but not the root cause, and the temperature will rise again once the effect of the drugs has passed. Some diseases generally last 3-5 days, and it is normal for the temperature to rise again after taking antipyretic drugs when the disease is not over. NSAIDs can generally be taken again after 4 hours, and the cause should be further investigated after 3 days of taking them without relief.