For cold and cough, you can try home remedies like; give him haldi waala milk, concoction of ginger, honey and mint water. If he sweats a lot, you change his shirt each time you feel he has become too sweaty and keep him hydrated by feeding water every now and then. Try home remedies and if still there's no relief, you must see a doctor. http://www.webmd.com/cold-and-flu/cough-home-remedies-babies-toddlers
Go for hemopathic medicine ... As they have really no side effect .. for cold n cough they r best ...