British endurance swimmer Lewis Gordon Pugh is a campaigner and keynote speaker about the problems and perils of climate change. His latest plan is to swim in the icy cold waters of the lake on the Khumbu Glacier more than 17,000ft up Mt Everest to highlight the climate change on the Himalayan glaciers.
Nicknamed 'the human polar bear', Lewis hopes to be the first to do the 1km swim. He will wear just Speedos, swimming cap and goggles and is hoping to be in the water for just 20 minutes.
The Himalayan glaciers which are a source of water to over 1.3bn people, are receding faster than in any other part of the world. With a 1 degree rise in temperature, there are predictions that the glaciers could be extinct within 25 years.
The mountain range's glaciers provide water to more than 1.3bn people and are receding faster than in any part of the world.
Lewis Gordon Pugh said "These glaciers are not just ice. They are a lifeline - they provide water to a fifth of the world's population.
"It's essential that politicians put aside their differences and agree a bold strategy to reduce climate change to below current levels when they meet in Copenhagen."
Lewis has previously swam for 20 minutes at the North Pole to raise awareness of the effects of rising temperatures on the Arctic.