As you r saying fever of 100 since 3 days and no other specific symptoms i would recommend to start an antibiotic keeping in mind infective pathology,viral fever
, u can start tab mahacef200mg twicedaily for 3days along with tab pan40(beforebreakfast daily once) tab zerodol-p thricedaily ( if he is an asthmatic or APD do not use this tab instead use tab dolo650 twice daily ) monitor his temp regularly give soft diet
and hydrate him with liquids . please kindly check his CBC,esr
, MP BLOOD TESTS.