The teams face some steep terrain, and high altitude takes its toll on a number of the challengers.

Bear challenges the teams to swim to shore from the middle of a bay and navigate waterfalls.

A helicopter takes the remaining teams to the base of a raging waterfall, which they must ascend.

The remaining contestants must cross a rope suspended 100 feet over a gorge.

The teams face the coldest night yet, and they must join forces to rappel down a cliff.

The four remaining teams must navigate the dangerous terrain on top of a glacier.

Drenched but determined to win, the remaining teams work on their own to show what they've learned.