Richard Madden has revealed how he risked life and limb to recreate the Klondike gold rush.
The Scot had to escape an avalanche by running towards it while filming the series, his first in North America.
And he was left hanging off a 9000ft mountain by a rope in a blizzard.
The former Game of Thrones star was thrown into raging rapids as he rafted down a river. And during filming of the epic Klondike, which premiered in the US two days ago, cameras froze at -38C.
Richard, who grew up in Elderslie, Renfrewshire, said: “It’s the hardest thing I’ve ever had to do. Klondike shows humans in the rawest form, where the stakes are literally life or death every day. Things are out of your control and how you react defines you as a person.”
Richard, 27, plays adventurer Bill Haskell, who escapes life behind a desk to join the 1890s Klondike gold rush to find fortune and love with entrepreneur Belinda Mulrooney, played by Abbie Cornish.
Richard’s most frightening moment came as they were filming above the clouds.
He said: “At that altitude, the air is so thin you can’t breathe but we were having to run uphill towards an avalanche – for shelter. We were at our limits physically. I always try to be as fit as I can but this was definitely the most physical job I have ever had to do.”
The actors were roped together, hanging off a mountain and buffeted by a blizzard while saying their lines, .
Richard – who is dating Doctor Who’s Jenna-Louise Coleman – said: “As an actor, you don’t have to pretend – you are simply in the elements the character is experiencing. We were at the end of our tether. The weather has been brutal and there were points when we were on a frozen lake where the cold was intense, reinforced by four huge snow machines – so the snow was really hitting you in the face.”
Klondike was shot in Alberta, Canada, and part way through, the location had to be evacuated after flooding.
At one stage, Richard – who is being tipped for Hollywood stardom after winning the part of Prince Charming in Disney’s Cinderella opposite Downton Abbey’s Lily James – had to throw himself into dangerous river rapids.
The actor, who played Robb Stark in Game of Thrones, said: “I tried to convince myself that it’s just a big set and they can turn off these river rapids whenever they wanted.”
Executive producer on the six-hour series was Aliens director Ridley Scott. He said: “Shooting at minus 20C and even -38C, it is stultifyingly hard.”