Fireman Jim is more used to hot conditions than ice and snow

Jim McNeill, who serves with the Royal Household fire service at Windsor Castle, left Heathrow Airport on Monday for the start of his 18-month trek from Canada.

The father-of-three from Berkshire hopes to raise £2 million for Cancer Research UK.

Braving temperatures of minus 50 degrees, he will pull his supplies on two specially designed sledges for 685 miles to and from the Arctic Pole - a trip which is expected to take him 70 days.

Record attempt

If he is successful, he will heading back to the Arctic later in the year to embark on a 1,000-mile trek to the Magnetic, Geomagnetic and Geographic North Poles.

Mr McNeill said his motivation for the record attempt was both the personal challenge and a desire to raise money for the charity after cancer hit his family.

The amateur adventurer's grandfather died of pancreatic cancer, his mother survived breast cancer and his personal trainer has been diagnosed with terminal ovarian cancer.

Realistically my chances of success have got to be 40-60 against Jim McNeil

"Cancer is such an insidious disease, it is difficult to find someone who has not been affected by it in some way, shape or form," he said.

"It is such a massive challenge to conquer cancer, that to be able to help Cancer Research UK is fantastic."

Mr McNeill's expedition is part of the Ice Warrior project he founded two years ago to increase the popularity of science in schools and tourism to extreme parts of the world.

Shackleton echo

During his trek, he will be carrying out experiments to examine the psychological and physiological factors which help human beings to survive in extreme conditions.

"It will be the hardest thing I have ever done - realistically our chances of success have got to be 40-60 against," he said.

"But success does not motivate me, I am motivated by the challenge."

Mr McNeill will be supported by a team of nine volunteers who answered a replica of explorer Ernest Shackleton's newspaper advert for his 1913 Trans Antarctic Expedition.