The swamps of the Everglades, Florida are killers - 60 visitors die annually, including three women attacked in just one week in 2006 by some of the two million alligators. Deadly snakes and scorching heat take their toll too. The Everglades is really a 40-mile wide river - a waterlogged, featureless landscape with almost no solid ground. Bear Grylls demonstrates how to survive in this alligator-infested swamp.