Jim Crosbie has coldly gone where none of his staff has been before.

For the 41-year-old, pictured, spent more than an hour in sub-zero temperatures to see if Bingley's famous thermal undies are as hot as they're cracked up to be.

And after chilling out with top stuntman Curtis Rivers - who appears in the hit film The Count of Monte Cristo - they both gave Damart's "double force" high-performance undergarments a sweltering ten out of ten.

As Damart's business development manager, based at the company's headquarters in Lime Street, Bingley, Jim said the coldest place he previously wore thermals was on a trip to the most northern point of Siberia where it was minus 20C.

But he said standing in an industrial freezer in temperatures as low as minus 43C yesterday was the ultimate test for the company's outer-clothes and underwear as it was so cold they had to keep blinking to make sure their eyes didn't freeze.

"Our thermals have been worn by top explorers at the North and South Pole but I wanted to do it myself to see how good they really are," said Jim, of Mirfield.

"It went really well and the only bit of me that was cold was my eyes which were exposed as I had a balaclava mask on. When I came out my eyebrows and eyelashes were frozen white."

But after just eight minutes in the 12ft by 14ft vegetable freezer his watch stopped and froze.

The experiment was also to test body temperature-monitoring equipment which Curtis, who was "killed" five times in the James Bond film Tomorrow Never Dies, will be using when he attempts to break three world records in a high altitude hot air balloon stunt called Operation Hawk in Spain next month.

He said he relied on his thermals for stunts in extreme temperatures.

"I used them in the record-breaking bid a couple of months ago and they were fantastic. I didn't feel the cold at all and I was in a hot air balloon at 33,000 feet where it was minus 55C," he said.

"I also successfully tested out new camera equipment which is able to withstand sub-zero temperatures to record my stunt."

Both men swallowed a special capsule which allowed scientists outside the freezer to keep tabs on their body temperature, which kept at a constant core temperature of 37.295 degrees.

Jim said: "I can't believe I survived. Curtis trains every day but I did no preparation, but it proves that wherever you are in the world you will survive if you've got your Damart thermals."

Curtis's record-breaking bid will include parachuting from 31,000 feet.

The 31-year-old aims to perform the world's highest static jump from a hot air balloon and glide for more than 40 minutes - a record unbroken for 45 years.

The record for the longest parachute fall of 40 minutes was set by American Bob Harris 45 years ago. He did not intend to set the record, but by a fluke he was caught up in a freak thermal.

Curtis attempted the records in February but the bid was thwarted by frozen camera equipment.

The stunt will raise funds for Cancer Research UK.