Lost in The Snow Former Olympic hockey player Eric LeMarque was snowboarding alone in the Sierra Nevada in 2003 when thick fog settled around him, limiting his vision to 10 feet. Soon he was lost in the snowy wilderness with no food and a dead cell phone. He wandered through 15-foot snowdrifts in freezing temperatures for seven days before National Guard searchers found him.
When exposed to bitter cold, your body shivers, and this involuntary movement creates heat the same way exercise does. If you stay in the cold and your body temperature continues to drop, shivering will stop when the muscles no longer have enough energy to move, says David Richard, a professor of biology at Susquehanna University in Pennsylvania. He teaches the course “Exercise and Extreme Physiology” and is an authority on the processes that sustain life under extreme conditions—and on what happens when the human body is exposed to more than it can withstand.
After prolonged exposure to intense cold, Richard says, your body’s chemical reactions begin to slow until they generate too little energy for your muscles to work. By carefully regulating blood flow, your body will protect your key organs while preserving your extremities—at least for a while. In the cold, blood is generally directed to the core of the body and flows only intermittently to the extremities to bring oxygen to cells there. After prolonged exposure to cold, blood travels only to the most essential parts—your brain and heart. As severe hypothermia sets in, these organs may be the only ones left functioning.