Bear Grylls

NBC reality trek Running Wild With Bear Grylls has made headlines in recent months for bringing high-profile figures out into the wilderness, but the survival series may yet have its biggest name ever, and all for a cause. Barack Obama himself will join Grylls in the wilds of Alaska, exploring some of the climate change of the region.

Proceed with caution.  Bear Grylls' Producer, Steve Rankin (right) was bit in the foot by a "Fer-de-lance" or "Velvet" snake and the before and after pictures are quite disturbingly NOT Safe For Work.  You've been warned.

On the season premiere of 'Man vs. Wild,' actor Jake Gyllenhaal took on a very different role: human popsicle. In order to stay dry while crossing a frigid river in Iceland, Gyllenhaal and Bear Grylls stripped off a portion of their clothing in sub-zero temperatures.