In 2003 Former Olympian Eric Le Marque was out snowboarding in the Sierra Nevada Mountains when a huge fog sent him off course along the 11,000 foot slope. He tried for days to make it back to civilization, but he was actually traveling in the wrong direction.
Despite what should have been a life-ending mistake, Lamarque survived for 8 days in the snow until he was found by a team that was looking for his body. Before this, the longest time anyone had survived conditions like these was 3 days.