10month old son have fever.itching scalp.little chest congestion.why and how cure.

A viral illness: If your son looks sick and lethargic, he needs to be seen by a doctor right away. If he has just fever (how high?) and chest congestion (cough? Runny nose?), and otherwise he is doing ok, it is most likely a virus. The itchy scalp may be due to sweating because of fever, and you may see little red bumps like heat rash.Most of the time, a viral illness runs its course and goes away on its own.