Former Special Forces adventurer Bear Grylls demonstrates how to survive in the world's harshest environments. When Bear is left in the middle of the Rocky Mountains, he must find his way back to civilisation.

Bear visits Utah where he demonstrates how to stay alive in the Moab desert, an unforgiving 3,600 square miles of canyons, cliffs and desert. Every year, 5 million tourists visit the region, but 200 are lost, injured or die. The first priority is to get out of the sun and the 110-degree heat to avoid the biggest killers: sunstroke and dehydration.

Bear's in the Costa Rican rainforest, a beautiful but hostile environment, and he decides to follow streams and rivers to the sea and the safety of the communities who live there. Bear follows a stream and scales a 120-foot waterfall using ropes made from vine.

Continuing his adventures, Bear is dropped into the Chugach Mountains by the Alaska Air National Guard and faces challenges including black bear-infested forests.

Bear Grylls travels to the island of Hawaii where he reveals how to survive Kilauea, the world's most active volcano and one of the toughest places on Earth.

After parachuting into a high altitude lake in the Sierra Nevada mountains, Bear demonstrates how to survive by heading west towards the coast and away from the Nevada desert. Almost immediately, he's forced to scale a huge cliff and risk a 350-foot drop from treacherous, slippery rocks. Following a river, he uses Native American techniques to build a raft, but later must abandon it.