By Anna Lindsay BBC News Online, Southampton

An adventurer has become the youngest Briton to reach the summit of one of the coldest mountains in the world.

The group spent 14 hours on the summit ridge of Mount McKinley.

Rhys Jones, who turned 17 four weeks ago, endured temperatures which plummeted to -70C on his final ascent of Alaska's freezing Mount McKinley.

During the climb to the top of North America's highest peak, which experiences some of the toughest weather conditions in the world, Rhys and his team mates took shelter from a vicious five-day storm.

Every half hour they were forced to dig their tents out of the snow to stop them from being completely buried.

Each climber entertained the group by reading aloud an entire novel of his choice until the storm finally lifted.

Speaking to BBC News Online from Anchorage, Alaska, Rhys - who comes from the New Forest in Hampshire - said: "It's been amazing. The climb took 22 days and we reached the summit at 18.

Severe altitude sickness made Rhys forget his own mother's name

"We were always confident we would do it but it depended on the weather conditions.

"Being stuck in the snow was quite demoralising but we had good camaraderie in the team."

The group, known as the Hampshire Scout Expedition, spent the final 17-hour leg of the climb scaling the summit ridge of the 20,320 feet (6,194 metre) mountain.

Carrying a rucksack weighing 80 pounds (36 kg) and dragging a 60 pound (27 kg) sled, Rhys began to suffer from altitude sickness, eventually becoming so disorientated he forgot his mother's name and what his ice axe was.

His team mates Nathan Figg, 28, from Alton, Hampshire, Mark Hide, from Oxford and flatmates Dave Frid, 23, and Tim Clarke, 23, both from Basingstoke, Hampshire, also began to suffer exhaustion.

Rhys, who spent three years training for the climb, said: "We spent 14 hours on the summit ridge where any slip is fatal. There is a drop of 4,000 feet one side and 1,000 feet the other.

"But you could see for thousands of miles, it was absolutely stunning.

"I was exhausted and cold but at the same time excited. You can't really describe it," he said.

The mountain is increasingly known by its native name, Denali, which means The Great One in the Athabaskan language. It is flanked by five giant glaciers and countless icefalls.

"My friends and family think I'm crazy and can't understand why I want to spend time in freezing temperatures, having to go to the loo in a plastic bag, when I could be enjoying the sunshine at home," Rhys said.

But conquering Mount McKinley is the first in a series of extreme challenges for the group, who intend to be on the summit of Mount Everest for the Scouting Centenary in 2007.

Rhys said: "This was just a training exercise. Next is the Alps and then Nepal's Cho Oyu in 2005 before we scale Everest."