Bear heads out to Zambia in Southern Africa, where he will show you how to survive the world's biggest rapids, and next will head into the bush.

Bear Grylls shows us Namibia, one of the hottest and driest places in the world. He soon meets with the San Bushmen, masters of desert survival and gets a lesson on how to survive there.

Bear continues his second week in Indonesia, the site of a devastating tsunami in 2004 by sleeping in the trees and navigating across waterfalls walking along sheer cliffs.

Bear parachutes into one on the coldest and harshest areas on earth, the Siberian tundra, where he will test himself against extreme challenges. Living in temperatures of minus 30 degrees, he must locate shelter before night falls.

In the final episode of season four, Bear heads to the Siberian tundra and the Sayan Mountains. Also included is a look at the survival skills used by the Tuvans, yak herders which are Genghis Khan's decedents, who are experts in surviving in cold climates.