British explorer Sir Ranulph Fiennes has spoken of his latest challenge - leading the first team on foot across Antarctica during the southern winter.

The 68-year-old will brave temperatures of minus 50C (minus 58F) during the expedition next year when his group will make the trip called the Coldest Journey On Earth.

The challenge is the latest feat of endurance by the explorer who is hoping to raise 10 million US dollars (£6.17 million) for Seeing Is Believing, a charitable initiative to tackle avoidable blindness around the world.

The group will also have scientific instruments and carry out readings and measurements for scientists.

"There is a huge, blank knowledge of the winter of Antarctica, what is happening to Antarctica during a period when the scientists can't normally get out there," Sir Ranulph told BBC Breakfast.

"Our caboose will be bristling with scientific instruments, for Nasa, for the European Space Agency."

Sir Ranulph has broken several records and led many expeditions to remote regions. He was described by Guinness World Records in 1984 as "the world's greatest living explorer".

He is famous for taking part in the first successful circumnavigation via both the geographical poles, completed with Charles Burton in 1982.

He also successfully reached the summit of Mount Everest in 2009 at the age of 65, becoming the oldest Briton to achieve this feat.

Speaking to the BBC, Sir Ranulph said he thought of his wife, children and a "hot bath" during arduous challenges.