Four years with fever and headache, no cough or runny nose, what is it?
Children 4 years old, fever and headache may be a trivial or serious infection. The first thing that comes to mind is a virus or strep throat. The second could be pneumonia, a viral infection or something more serious like meningitis. I wonder if better after taking ibuprofen if you have ezcemas, sore throat, swollen tonsils ... If in doubt consult with your pediatrician.