This quick TED talk entry is courtesy of TED.com. After he swam the North Pole, Lewis Pugh vowed never to take another cold-water dip. Then he heard of Lake Imja in the Himalayas, created by recent glacial melting, and Lake Pumori, a body of water at an altitude of 5300 m on Everest — and so began a journey that would teach him a radical new way to approach swimming and think about climate change.