The best course of action is to call for help from a team of emergency medical services (EMS) personnel, who are trained and equipped to handle the situation. Having a satellite phone or a ham radio in camp can be a literal lifesaver. If there's no way to contact anyone, you're going to have to handle the crisis to the best of your abilities, and that means being prepared. If you're the victim, you may need to direct the activities of the others in camp trying to help. Tell them what to do. If possible, contact someone who can initiate a medical rescue--the sheriff, the park rangers, the nearest hospital, etc.