Yay someone posted about cooking meat. Lol. I'm not saying there should be fully working machines in there or anything, but its actually not totally unrealistic that a hospital got overrun before the grid went down and they began using the generators. Realistically you could go start up the backup generators and use the machines then shut them back off. Anyhow, that's not my suggestion. Stitch up your cuts, sterilize your wounds, rest, etc. Do things that can't really be done well outside of a hospital and you'll start feeling better. Or if you wanted it super simple the hook your blood bag to the IV rack and lie down and get restored. If you lose blood you don't get a transfusion. You get blood. Transfusions replace your current blood with an equal amount. Falling off a roof didn't make you blood bad or poisoned where you need a transfusion You lose blood and need replacement blood. Hell add orange juice and cookies as these help boost your blood cell creation.