Most fevers in children are viral in origin and take 3-7 days to subside completely. If not accompanied by any other symptoms like vomiting or loose motions or coughing and breathlessness or dullness and refusal to feed,just give paracetamol for fever and repeat every 4 hours if required. Ensure proper feeds and extra fluid intake. If not improving OR accompanied by above,consult your paediatrician.