hello drlavanya428, fever in child-in 2.4 old baby- usually viral but you did not mention body weight, neither given history fever with chills & rigors,breathing rate,common cold,burning in micturation,motion either loose or constipation, advice- HB,TLC & DLC,ESR, urine rourtine & microscopy, if breating rate more than 40 per mintue or dyspnea, then- X-ray chest- PA veiw, if loose motion with blood then X-RAY abdomen , treatment depends upon under lying condition e.g. for dehyration need iv fluid supplemenation, for breathlessness need- antibiotics, like amoxycillin or septran , for urinary infection- amoxycillin or septran effective, medicine dose cannot calculated because body weight did not mention, hope my advice is useful to you,thank you