You first heard about it a few weeks ago, but now you finally get to see Jake Gyllenhaal take his shirt off on 'Man vs. Wild' (Mon., 9PM ET on Discovery). Well, there was more to it than that.

He and Bear Grylls both shed their shirts in sub-freezing temperatures to keep them as dry as possible while they crossed a river. It's a far cry from a shirtless Gyllenhaal in the deserts of 'Prince of Persia.'

"I joined up for this, right?" Gyllenhaal lamented as he stripped. They made the crossing fairly quickly, making us cold just from watching them in the freezing water with the cameraman trying to keep the lens free of snow and ice.

The pair were hoping for a fun adventure, but the Icelandic weather proved worse than Grylls had anticipated, leading to some pretty harrowing moments. But Gyllenhaal was a trooper and proved rather capable and adept. All that working-out for movies came in handy in the great outdoors.