The new adventure epic Everest dramatises a real-life event from May 1996, when the mountain was packed with climbers just as a freak storm rolled in. Of course, even in ideal conditions, the world's tallest mountain is an enormous challenge. As team leader Rob Hall (played by Jason Clarke) says in the film, "Human beings simply aren't built to function at the cruising altitude of a 747."

Everest castEverest tells the true story of mountaineering's most shocking disaster

Clarke was familiar with the story. "I was doing theatre in Sydney in 1996, and during a tech rehearsal it was on the news," he recalls. "By the time I heard about the film, I had read the book and visited base camp as a traveler."

More: Watch the 'Everest' featurette

Preparing for the role was a challenge. "We went and did some great climbs," Clarke says. "That's a benefit: somebody pays you and gives you a great guide! At Christmas, we were rehearsing in London and there was a massive storm. We grabbed a guide and did night climbs on Ben Nevis. The big winds were great for that feeling from the end of the film, for us to be in atrocious weather in the dark. It's not quite the same as pulling 14, 15 hour days in Pinewood on concrete floors while they blast salt at your retina!"

Watch the trailer for 'Everest' here:


 

Co-star Jake Gyllenhaal agrees that this wasn't the usual film production. "This project attracted people of similar minds," he said. "For an actor, there is something appealing about putting physicality into your role, where you're actually experiencing something and not just faking it. There was a good deal of stage work, but a lot of it was out in the open: shooting in the environments, not being able to breathe, struggling and helping each other in different ways. You're not separated from the process, you're actually working with the crew as if you're on an expedition."

More: Read our review of 'Everest'

Josh Brolin gives credit to director Baltasar Kormakur, saying that "Balt seduced us with the way he wanted to approach this. He said, 'As much as a production company can document what you guys are going through as these characters, we're going to try to be as true to that as possible.' The people I know who are actual mountaineers, they beat to a different drum. Something pushes them to do something that dangerous. I'm sure they're normal guys, but not normal like you and me."