Wounded soldiers train in Iceland for South Pole race

In one of the worst storms anyone in Iceland can remember, a group of badly injured servicemen and women from around the world have been struggling through howling blizzards on the edge of a mountain glacier.

They are training for Antarctica and a coming international race later in the year that will stretch them 330km (205 miles) across the frozen wastes to the South Pole.

Every member of the three competing teams, from the UK, the US and the Commonwealth (in this case Australia and Canada), has been either shot, burned, blown up or traumatised in combat operations.

Many are missing limbs and one, US Army Capt Ivan Castro, is totally blind after losing his sight to a mortar bomb in Iraq.

Buffeted by the wind, unable to see the contours ahead of him, he is finding it harder than most.

"I've fallen over so many times I've lost count," Capt Castro shouts above the wind.

"Yesterday I only fell four times but this time I've lost count. It's extremely tough for me, I have to say. Since I lost my sight this has been one of the toughest things I've ever done."

Hazards and hurdles

The South Pole 2013 challenge is being organised by the UK charity Walking With The Wounded (WWTW) - whose patron is Prince Harry - to raise awareness of wounded servicemen and women returning from conflict and trying to assimilate back into civilian life.

There is no talk of politics, of the rights or wrongs of being sent off to somewhere like Afghanistan. All the focus is on rehab and recovery, mental as well as physical.

Last year, they made an attempt to climb Mt Everest, but had to turn back just before the summit due to bad weather.

The year before that, WWTW's British team successfully trekked across the polar ice cap to the North Pole, with Prince Harry accompanying them part of the way, leaving them with just days to spare before his brother Prince William's wedding to Kate Middleton.

This year, it is different.

Trekking across Antarctica brings its own hazards and hurdles.

For a start there is the altitude. Unlike the North Polar ice cap, which is all at sea level, Antarctica is a landmass that rises steadily up to over 4,000m (13,000ft).

The winds are legend and the continent holds the record for the lowest recorded temperature on earth: -89.2C at Vostok station.

And Walking With The Wounded has now gone global.

Determinedly upbeat

The Commonwealth team, made up of Australians and Canadians, will be racing against Britons and Americans.

Despite the camaraderie and the banter, it is likely to get fiercely competitive.

At the foot of a black, volcanic mountain I find the Commonwealth team hunched against the gale and wolfing down mouthfuls of some glutinous meal.

With all their backs turned against the wind I can't help thinking of those flocks of Antarctic penguins huddled miserably against the blizzard.

Some of the Australians are from the subtropics and are now getting their first taste of snow.

Despite the vile conditions they are determinedly upbeat. "It could be colder," jokes one. Another reminds himself why he is putting himself through this ordeal.

"Being able to raise awareness of wounded soldiers through charities like Walking With The Wounded and Soldier On," says Heath Jamieson of the Australian Army, "provides avenues for the public to get behind their wounded soldiers."

Meanwhile, the British team, clad in bright red tops, have planted their skis some way off.

There is no natural shelter to be had anywhere, for any team, which is exactly what will face them in Antarctica.

Only one of the Britons, Guy Disney, has been on a polar expedition before with WWTW.

A former British army cavalry officer, he lost his leg in an explosion in Afghanistan. Yet, equipped with a prosthetic leg, he successfully trekked with the rest of his team to the North Pole in 2011.

I ask one of his new team mates, Jason Wilkes, how he is finding the conditions.

"The problems are just the wind and the skiing and also people have never skied before, the amputee guys, they're just getting used to it," he replies.

It would seem a fitting time if he and his team were having any second thoughts - after all, this hardly looks like fun.

"None at all Frank, none at all," he says, grinning, as he skis off into the wind. He might even be whistling.

You can follow news of the race, the participants and their training on Twitter #southpole2013