What remedy does Ralston give himself after sustaining an injury on Capitol Peak instead of going to the hospital?

While climbing Capitol Peak, Ralston develops frostbite on several of his fingers on both hands. Instead of going to the hospital for treatment, he takes pain-reducing medications of his own at home. Then he places his hands in a hot water basin, waiting for blisters to form. According to Ralston, if blisters form the fingers have a chance to heal. Since they do blister, he does not go to the hospital.