Ibuprofen is an emergency fever reducer, and most children will have their fever reduced within half an hour to two hours after taking it. The reason why the fever does not drop, first of all, depends on whether the dose of the drug is eaten to the full amount, and the other is the lack of water in the body. How to determine the dehydration of the body? We need to see if the child’s skin is dry, if the amount of urine is high, and if the mouth and lips are dry. If there is dehydration, the fever will not go down within 2 hours even after taking ibuprofen, and sometimes it will not go down even after 4 hours, then it is highly suggestive of dehydration and a lot of warm water should be added. If you really can’t drink warm water, you can also mix some drinks or fruit juices, as long as there is water, you can eat more, supplemental hydration.