The first programme, to be broadcast on Sunday, shows Tom Hardy and Salo taking on the 1,260-mile Kolyma Highway after being warned that the temperatures, which can fall below -70C, are so cold that their fingers are likely to fall off if they remove their gloves for too long. The expedition leader points out that even marines stop training when the temperature gets below -30C.
Unable to drive, Hardy, above — who is due to play the explorer George Mallory in the film, Everest — watches from the passenger seat but is still called into action to change a punctured tyre. Later, despite the biting cold, he takes the opportunity to swim in an ice-covered lake.
Salo said they were cracking jokes all the time and there was no shortage of funny moments, not least when one of them had to answer the call of nature. “You jump out of the car but then you can’t take your gloves off,” he says. “How do you do it?
“We didn’t realise how serious and dangerous the situation was until we got out there. I’m from Finland but I had no experience of how cold it was going to be. We had to leave the car running all week so that it didn’t freeze up. If something had gone wrong, we would have died.”