Everest: how Jake Gyllenhaal got to grips with the world's highest mountain

As his film about the ill-fated 1996 expedition opens the Venice film festival, director Baltasar Kormikur explains how he and his cast coped with difficult conditions and delicate subject matter

Imported snow from Holland was among the secret weapons deployed by Everest director Baltasar Kormikur in his quest to make his 3D film about the disastrous 1996 expedition, when eight climbers died on the world's highest mountain, as realistic as possible. "It was the real stuff, minus 60 degrees; when we were shooting at Pinewood, we blasted it in their faces as hard as we could."

"I wanted the actors to respond to the environment," Kormikur said. "The more you draw from reality, the more likely you are to get reality." Everest, which features Jason Clarke and Jake Gyllenhaal as Rob Hall and Scott Fischer, leaders of rival expeditions on the mountain, both of whom died in the tragedy, has been given the prestigious opening-night gala slot at the Venice film festival.