The team has already suffered from frostbite during the training
Two polar explorers from Devon are undergoing final tests in Canada before the start of a major scientific survey.
The pioneering £3m expedition will plot the future of the Arctic ice cap.
Pen Hadow, who lives on Dartmoor, and Ann Daniels, of Whimple, will use specially-built radar to measure the thickness of the ice.
About 10 million measurements will be taken to help scientists to calculate more accurately how long the dwindling ice cap might last.
Mr Hadow became the first explorer to trek solo and unsupported from Canada to the North Pole.
Ms Daniels, who has four children including teenage triplets, was a member of the first all-women teams to trek to both the North and South Poles.
The third member of the survey team is specialist polar photographer Martin Hartley.
The trio have been rehearsing their daily routines in temperatures as low as -30C at Broughton Island, in northern Canada.
They are also practising their drills and tasks, as well as checking the scientific and life-support equipment is performing correctly.
On occasions the trio will have to swim between ice floes pulling their sledges
Mr Hadow said training conditions were tough, with Broughton Island in darkness for about 20 hours a day.
"You can't see your hand in front of your face, and if your overhead torch goes out, that is it," he said.
During trials in November, the team suffered varying degrees of frostbite to their faces and limbs.
But Mr Hadow said it was vital the trials were carried out in extreme conditions.
"We need to be sure we work well as a team, so our daily routines for trekking, eating, science work and so forth have to be practised so we are in the best possible shape when we cross the starting line," he said.
"After years of preparation, that will be our moment of truth."
The three-month Catlin Arctic Survey expedition to the North Pole is due to begin at the end of February.
The team will take samples of the water, snow, ice and air as well as measuring the water column under the sea ice and recording density measurements of the snow and ice.
A data uplink system will transmit findings to scientists direct from the ice via satellite.
An Inuit clam-diver, who has been diving in sub-zero seawater for many years has been giving the team members advice, as they will sometimes be forced to swim across open water pulling heavily-loaded sledges.
Ann Daniels was a member of the first all-women team to trek to both poles
During the Broughton Island training, Mr Hartley will use an underwater camera to capture images of the team swimming in sub-zero temperatures.
He will also use a night-vision camera to film the team crossing the ice in complete darkness.
Current estimates of how long ice will be a year-round feature around the North Pole vary considerably - with scientific predictions ranging between five and 100 years.
The project aims to help fill the current gap in existing measurement studies by satellites and submarines - which cannot differentiate between ice and snow layers.
Once the survey has been completed, the findings will be made available for the United Nations Climate Change Conference of Parties in Copenhagen, Denmark, next year.
The project's patron is the Prince of Wales. It is supported by the United Nations Environment Programme and World Wildlife Fund International.