What Causes Fever, Vomiting And Excessive Saliva?

Hi, my 2 yr old son is having fever ranging from 100 - 102 deg F since 2 days. Also, there is a lot of salivation along with vomits. He is not taking anything to drink or eat except water, not even milk. I am giving him paracetamol and anti fever patches for treating fever. There is no other symptom like cold or cough or sore throat. Pls suggest