The Science of Reviving the Dead

Five minutes without oxygen is indeed fatal to brain cells, but the actual dying may take hours, or even days.

That the five-minute rule is not absolute has been known for a long time, and the exceptions seem to involve low temperatures. On Napoleon's Russian campaign, his surgeon general noticed that wounded infantrymen, left on the snowy ground to recover, had better survival rates than officers who stayed warm near the campfire. Scientists are now hoping to harness this effect to save lives today.

Back to Life: The Science of Reviving the Dead - Newsweek Technology - MSNBC.com