Sir Ranulph Fiennes admits he "should be ten years younger" as he attempts to climb one of the world's most dangerous mountains, Argentina's Aconcagua.
The 72 year-old has started his ascent of the highest peak in South America as part of a world record attempt, which could see him become the first person to climb the highest mountain on every continent and cross both polar ice caps.
The explorer from Somerset will face blizzards and temperatures as low as - 30 degrees celsius. If he completes this challenge, he'll have two more summits to complete in Alaska and Australia.
He spoke to ITV News via skype from Aconcagua's base camp:
Sir Ranulph is a veteran of dark, freezing expeditions, and after spending a lifetime punishing his body, he has the scars to prove it:
Four fingertips lost to frostbite in the Arctic.
A respiratory condition, made worse by low oxygen levels.
Two heart attacks which have led to double bypass surgery.
A fear of heights.
His latest challenge is part of a 30 year fundraising effort, which has raised more than £18 million for charity. After his wife died, Sir Ranulph Fiennes has been campaigning specifically for Marie Curie.
The nurses helped provide end of life care, which he says made all the difference.