Good morning, going by the details , i feel that the child may be having viral fever
with a rash
for fever , u can give him warm water sponge baths, oral paracetamol
or mefenamic acid
based compounds, for his running nose you can give him antihistamines like citrizine or cholrphenaminemaleate. maintain hydration and nutrition. the doses of the above said drugs should be adjusted acoording to the weight of the child , so get a doctor to examine him and then start the medicnes. thank you.