Drink plenty of fluids, one of the best to drink is a sports drink like Gatorade, these help to rehydrate the body. Get plenty of rest, illness is usually a sign of the body needing rest. Also, if you do start to vomit as awful as it is don't fight it. That's easy for me to say I know because I'm not the one doing it and to be honest I hate doing this as well. But guess what after doing it a person usually starts to feel better. Becasue vomiiting is one way that the body wards off an illness, I could go into the other way, but well we can figure that out for ourselves.