You’ve been searching on foot for the past two days in a wet snowstorm for a lost hunter. Last night the skies cleared and the bottom dropped out of the thermometer. It’s a 0 ° F dawn. The snow is knee deep. Your hunter has now spent two nights out.

The radio crackles with a report that the subject has been found and is being evacuated by sled to the search base, a large nearby log cabin. You head over in time to see the patient, in a sleeping bag, being carried into the cabin. They found the hunter face down in the snow. He had apparently fallen into a creek sometime during the early morning hours (the ice had not re-frozen).

Your initial assessment finds the patient responsive to pain with a barely audible moan. You cannot find a pulse and there is no apparent respiratory effort. With a stethoscope you find a heart rate of 30 and a respiratory rate of 6. In order to do the head-to-toe you need to cut through 2-3 layers of frozen cotton garments.