When someone gets hurt or infected, its usually very painful when the doctor works on that exposed area. The only reason why you feel the pain is because the nerve ending shoot electrical signals to your brain. Would it be possible to devise an electromagenetic collar that goes around the arm or leg that prevents any electrical stimulation your nerves shoot from going past the collar. Granted, you would have total loss of your body past the collar, but thats just until the doctor stiches you up. Afterwards, you would regain use and only feel the numbness normally felt after a cut, but not the intense pain during. It would mean they could operate on your arms/legs while you're awake and you wouldnt feel a thing!