Shock
Shock is almost as deadly to injured people as the injuries themselves. It's best to treat all victims the same, regardless of whether they're showing signs of shock.
Lay victims down on a flat surface and make sure they're warm. Remove any wet gear that could prevent them from warming up. Make sure unconscious victims are laying in a position where they won't choke if they vomit.
Keep a conscious victim's head lower than their feet and have them rest for at least a full day. Feed them warm foods and sugar water to keep them comfortable.