When children have a fever it is important to prevent dehydration. Many of us worry too much about the fever and suppress it with Tylenol and Motrin.
Fever is beneficial the vast majority of the time.
In thirty-five years of practice I have never seen a fever that caused a problem. The disease that caused the fever was often a serious problem but the fever itself was not. Elsewhere I have recommended parents can treat fevers and gave the doses of medication to do that. Suppressing the fever will likely delay the healing process. But when a child has a fever and one is just observing the child and not treating the fever it is important to keep the child from dehydrating.