The cast and crew of Jake Gyllenhaal's new mountaineering movie Everest had to be evacuated from a location shoot after coming down with altitude sickness while filming in the Himalayas.

Director Baltasar Kormakur filmed some mountain scenes near the Mount Everest base camp, but the moviemaker and his team struggled to cope with the tough conditions.

Kormakur says, "We walked almost up to base camp, no vehicles are allowed there... at that point, we were shooting at the climber's memorials, people started to get sick, and we had to evacuate pretty quickly. It's one thing climbing up a mountain, which is really hard in itself, but it's another to work a 12-hour day when you get there."

The Deep filmmaker admits he was hard on his team while making the movie, telling the U.K.'s Guardian newspaper, "There's a difference between pain and injury, I put them through a lot of pain, but no injury."

It was previously revealed that the film's stars, including Gyllenhaal and Josh Brolin, spent time in an altitude simulator before filming began.

Everest, based on the story of the 1996 Mount Everest disaster that killed a number of climbers, premiered at the opening day of the Venice International Film Festival in Italy on Wednesday (02Sep15).