Bear brings along a companion, actor Jake Gyllenhaal, to test how he measures up to unpredictable and unforgiving Mother Nature.

Grylls is kicked out by helicopter into the water near a deserted island in the Pacific Ocean. He demonstrates long distance swimming, shelter building and coconut harvesting. Grylls builds a bamboo raft to look for ships, and is surrounded by tiger sharks. He fishes off his raft using a fish bone hook, and shows how to signal a ship using the reflection produced by his polished knife.

Grylls heads to Romania where he takes on a bear and dangerous water channels.

Grylls parachutes into the Sierra Nevadas, simulating the situation of the hundreds of hikers who become stranded there each year. Equipped with a knife and a canteen, Grylls travels through the alpine, woodland and chaparral areas of the mountains. He unsuccessfully tries to tame a wild horse, and eats a live snake. Using techniques gleaned from the Mono Indians, he brushes his teeth with a manzanita leaf. Most of the ground he covers is traversed by river, using a raft held together by grape vine.

Grylls paraglides onto the edge of the Andes and follows rivers into the Ecuadorian jungle, is attacked by huge colonies of spear-nosed bats[disambiguation needed], and observes giant weevil grubs and piranhas. He builds a bamboo bridge and a bow and arrow to successfully catch fish, but it doesn't always go his way and he's forced to ride the rapids of the Amazon on a single tree trunk.

Grylls shows how to navigate the Cairngorms region in extreme weather using ice formations and moss growth, and how to test snow slopes for avalanche potential. He uses moss to purify water and skins a red deer for shelter. For food, he traps a rabbit and cooks it to demonstrate how to prepare it. Grylls also crosses deep marshes and uses fallen trees to cross ravines.

Grylls drops into the swamps of Florida's Everglades, where at least 60 tourists need to be rescued each year. He trudges through the swamp and shows how to construct shelter, deal with razor-sharp sawgrass, get out of a muddy sinkhole and avoid alligators and rattlesnakes. He eats frogs and cooks a turtle Seminole-style.

Grylls heads to Turkey where he deals with dangerous animals and he also takes to the water.

This week Bear braves the remote wilderness of New Zealand's South Island, crossing the country's tallest mountains and attempting to start a fire with wood that is soaking wet.

Host Bear Grylls parachutes alone into a remote area of the Rocky Mountains equipped with only the clothes on his back.

Grylls is dropped in the Chugach Mountains in Alaska, with skis and his usual gear. He demonstrates Glissading as he traverses snow and glaciers, and climbs down a 200ft (61m) waterfall. He catches a salmon, which he eats raw, and finds a skiff from an abandoned lodge. The skiff sinks, but he reaches the shore and is spotted by a ship.

Grylls parachutes into the extreme landscape of Iceland, the site of vicious blizzard, 50 mph (80 km/h) winds, icy glacial waters, boiling hot mud and volcanic springs. He demonstrates how to make a snow cave, find water in volcanic underground tunnels and avoid frostbite. To find food in this subarctic environment, Grylls scavenges a sheep for its eyeballs and mutton fat, and catches a ptarmigan. He demonstrates with his shoelaces the boiling of the eyeballs and mutton in the geysers, to save digestion energy and disinfect the scavenged food.

In the Kimberley region of Australia, an area with a mixture of huge scrub deserts, dry riverbeds and red sandstone cliffs full of deep gorges, Grylls faces extreme heat, poisonous snakes and the ever present danger of dehydration. Survival tips include how to forage for food (bush tucker), build a shelter and how to prevent sunstroke. He explains why he believes drinking ones own urine can prevent death from dehydration. During his journey, Grylls observes saltwater crocodiles and endures a lightning storm.

Grylls must cross blistering desert and barren salt plains in Mexico's Baja peninsula. While collecting honey Grylls is stung by a bee and his face becomes severely swollen, nearly blinding him.

Grylls has some tips on how to survive the hurricane season and he also eats a cooked tarantula to survive. He tells us about the hairs on the tarantula's back legs and how they defend themselves using the hairs.

In Mexico, Grylls must find his way out of Copper Canyon, and his only supplies are a water bottle, a flint and a knife. He demonstrates how to build a simple compass and climb sheer cliffs safely. For shelter, he uses ancient caves and makes fire with a traditional "fire saw." Grylls also demonstrates techniques for finding scorpions or grubs and fishing without a rod or line.

Grylls enters the swamps of Louisiana where he kills an alligator with a knife, and catches a catfish with his bare hands

Grylls jumps from a boat a kilometre off the west coast of Ireland. He travels down the coast before turning inland to cross the bogs. Here he retrieves a sheep carcass from a bog whose skin he uses as a sleeping bag (sheeping bag), a waterproof sack, and a flotation device.

Grylls takes on the deepest river based canyon, Hell's Canyon and the dangerous Snake River.

Grylls is on a desert island, south of Papua New Guinea. He wades across a shark-infested tidal channel, climbs crumbling volcanic cliffs, leaps over a 100-foot death drop, and constructs a bamboo windsurfer to make his escape.

Over 100 people drown each year in New Zealand, and Bear must cross a raging river on a tree trunk to head toward civilization. On his journey to safety he runs out of water, is forced to climb up active volcanic ranges and scale down a waterfall.

Bear Grylls is dropped by a helicopter into the Moab Desert in Utah in almost 45 degree temperatures, with nothing but a knife, a canteen, and a flint. He battles dehydration by soaking his t-shirt in urine, and eats two raven eggs, one raw. Lastly, he demonstrates how to escape from quicksand before swimming across the Colorado River. He also explains how to use the flow of rivers as tools to find civilization.

Grylls parachutes into a Costa Rican rainforest in the Osa Peninsula, with only his knife and a canteen. He's careful about the water he drinks, but gets violently ill anyway. He climbs down a waterfall using a vine, and floats down a river to the ocean on a raft he crafts out of balsawood to demonstrate how someone lost in the jungle can make it to civilization. He encounters snakes, mosquitoes and dangerous river currents.ve swamps.

Grylls parachutes into the Sierra Nevadas, simulating the situation of the hundreds of hikers who become stranded there each year. Equipped with a knife and a canteen, Grylls travels through the alpine, woodland and chaparral areas of the mountains. He unsuccessfully tries to tame a wild horse, and eats a live snake. Using techniques gleaned from the Mono Indians, he brushes his teeth with a manzanita leaf. Most of the ground he covers is traversed by river, using a raft held together by grape vine.

Grylls parachutes into the French Alps with a knife, a canteen, a cup and a flint, taking the parachute with him. He demonstrates how to survive falling into a frozen lake, how to build a snow shelter, and how to use a self arresting device to stop from plummeting into a crevasse. He also eats maggots and uses them to catch a trout. He performs a Tyrolean traverse and makes himself a pair of snow shoes out of young trees and parachute lines.