Cough and fever could be sogns of infection. U did not mention your childs weight and also what medication he is on. If he is not taking anything.. you can use paraceetomol syrup as per previous prescrption. If and previous cough syrups as precribes by your pediatrician you can start. It has been 3 days now if fever is coming down than its ok. If fever continues consult your pediatrician.
Health Tips
Give him luke warm water to drink
If child coughs continuosly give him a teaspoon of honey.
Don't give him biscuts,choaclates or cool drinks or cold water.
Avoid aircooler directly to the child. Note the point that room should be cooled not the child.