Does anyone have any tips for vocalists/performers on staying healthy?

Practice, practice. : But i'm not referring to practicing singing/performing. I'm talking about practicing good hygiene, good eating habits, and regular exercise. You've got to keep your body, especially your lungs, in shape to develop and maintain stamina. You should do things that involve good breath control such as swimming. You must avoid smokers, even to the point of being rude and discourteous if necessary.