Nick Jonas stripped down to his underwear to cross a frozen lake on a recent episode of Running Wild with Bear Grylls.

Nick Jonas Get Naked On ‘Bear Grylls’

Jonas appeared on Running Wild with Bear Grylls Monday night, the show’s season 3 premiere. At one point, Jonas had to cross an icy lake in the Sierra Nevada Mountains with adventurer and survivalist Bear Grylls. In order to keep his clothes dry in a waterproof pack, Jonas had to cross the lake in just his boxer briefs.

Though Jonas was clearly struggling during the freezing ordeal, his face bright red in the cold atmosphere, he kept his talk positive. “We can do this,” he said. “We got this.”

Once he arrived on the other side of the lake, Jonas, who is a diabetic, struggled to warm back up and get his circulation running normally again. Grylls helped Jonas recover and get feeling back in his extremities.

“My toes are freezing,” Jonas admitted. “It’s crazy what happens to your body, the instincts that kick in. You just have to go, push yourself.”

In addition to the lake-crossing, Jonas had to weather a meal of bird guts.

Courtney Cox will be the next celebrity appearing on Running Wild with Bear Grylls. The two will go on an excursion in Ireland on the episode that will air Aug. 22 at 10 p.m. EST.