make sure you dont he doesnt have a vitamin defficiency otherwise getting sick could be the norm for him, while sick its best that he gets a regular amout of fluids ( no seminal wont do ) in the form of water. regulate his body temperature so as to make sure he is in fit form to combat the cause of the sickness, all this means is keep him warm, not too hot and lastly get plenty of rest. Drinking sodas and the like are not reccomended and chicken noodle soup is delicious especially when sick.