Andy Torbet tries to match his skills against some of the most powerful animals in the world. Andy travels to Alaska in his quest to swim like a seal in freezing lake water, under a sheet of ice. His journey begins off the Northumberland coast, diving with grey seals to learn how insulating, fatty blubber gives them unrivalled cold-resistance. Next Andy meets Olympic medallist, Keri-anne Payne, and discovers how cold-water shock affects his body. Then Andy tests out blubber-like insulating technology while being dunked in the Extreme Environments Lab pool at Portsmouth University. Will this chilly challenge see him sink or swim?