hi Its Dr Gupta since your child is two year and duration fever is of short d most of screening test seem to be normal ( CBC, Urine, CSF) . but you have not mentioned about CRP . with symptom and sign we can give only possibility of few disease 1 viral fever 2 malaria get two investigation malarial parasite , C-reactive protein if these tests are negative give only paracetomol orally . if fever did not resolve do hydrotherapy give antiemetic . and wait to find out localised sign and symptom