Touching The Void star Josh Williams was able to draw on personal experience for his role as climber Joe Simpson.
The actor, who plays the man left for dead on a Peruvian mountain, travelled to the area aged 12 for a 2007 children’s BBC reality show called Serious Andes.
The 24-year-old from Twickenham said: “It was part of a CBBC programme that took young people to various different extreme environments around the world ... I went to the Andes for three and a half weeks. I had altitude sickness which was grim, and then attempted to climb Cotopaxi which is one of the highest active volcanoes in the world.
“I didn’t make it but I was only 12 so I’ve got unfinished business ... I’m going to go back another time to finish that one.”
The cast also climbed in the countryside near Bristol while performing an early version of the show at the city’s Old Vic. Williams said: “You get that sense of having your partner’s weight and taking that weight and having that trust.”
