After he swam the North Pole, Lewis Pugh vowed never to take another cold-water dip. Then, he heard of Mt. EverestÂs Lake Imja  a body of water at an altitude of 5,300 meters, entirely created by recent glacial melting  and began a journey that would teach him a radical new way to approach both swimming and how to think about climate change.
http://scientopia.or...-mt-everest-swim/
9 minute video at above site. It's mind-blowing.