I started out wanting to swim in places where nobody had swum before: Antarctica, the Arctic, all the bloody-cold places. I wanted to be a pioneer, a descendent of Scott and Amundsen, except an explorer of the oceans. I think I was born to swim, but standing on the ice edge at the North Pole in just a Speedo and goggles, I was terrified. You dive in and the water's 28 degreescolder than what killed the Titanic's passengersand it's like a death zone. It feels like somebody punched you in the stomach. You cannot breathe. Your skin is on fire. But doing this also gives me an opportunity to shake the lapels of world leaders who aren't taking the environment seriously. In 2008, I swam north of Spitsbergen and was so shocked by how thin the sea ice had become I called Gordon Brown on my satellite phone. We had a long chat. Shortly after, he appointed a climate-change minister in Britain.
In May, Pugh will attempt a one-kilometer swim through the near-freezing waters of an unnamed lake, at about 18,000 feet at the foot of Everest.