James McCoy, 23, from Merseyside, Mike Worsley, 26, and brother-in-law, Shaun Hudson, 37, both from Herefordshire, are raising cash for charity.

The three men and seven other teams from around the world have entered the Polar Challenge 2005 next April.

They will set off from the former North West Territories of Canada and the race is due to last for about three weeks.

Polar bears

Mr Hudson told BBC News Online: "Mac saw it advertised on TV and it just snowballed, if you'll excuse the pun.

"All of us are new to it but it's a once in a lifetime thing.

"We'll get into the hills in Wales for as many weekends as possible to get used to walking for eight or 10 hours a day and to work out what kit to carry."

Temperatures are likely to range from -20C to -65C with a wind chill.

The men will face frostbite, dehydration and possible attacks from polar bears, but competitors will be supported by crews in the area and they will have satellite telephones.

Money raised by the team will go to Acorns Children's Hospice and Cancer Research UK.

They will set off from Polaris Mine on 22 April 2005.