Bear Grylls knows something about fear. After all, it's his job to place himself in life-threatening situations. He uses his wits and survival experience to entertain and educate the viewers of "Man vs. Wild."
Grylls has faced countless dangerous situations, but we're treated to a real nail-biting moment when he crosses a murky, alligator-infested river. Grylls explains that alligators can easily mistake swimming humans for turtles or other common prey, and that he'd be virtually powerless if one of the supersized reptiles were to strike. When he dives in, knife tightly clutched in hand, Grylls is visibly frightened. Though he makes it to the other side in one piece, it's perhaps the scariest segment of a show built on outdoorsy thrills.