in a child indicates infection in most of the cases. For controlling fever give him Calpol
syp. 5 ml thrice a day, you can give it 4 times a day if fever is more frequent. Along with that do tepid sponging( with lukewarm water) . Now most common cause of fever at this age if not associated with any other obvious symptoms is viral infection, which needs conservative management only. But proper evaluation of cause of fever is needed in children below three years if it persists.
So I would suggest you to consult your doc for proper clinical evaluation and management accordingly.