My 2 years son have fever for one week without any other symptoms at all , his tepm reach 40.3 and its come down directly after give him fever medicin?

Doctor Visit: It is not normal for a child to have a temperature over 38 for more than 2-3 days. A child with persisting fever should be evaluated to find a source for the fever. Possible causes would include an ear infection, sinus disease, streptococcus in the throat or a bladder infection. A doctor visit can often determine the source of the problem.