Shooting Everest wasn't exactly easy.
The cast and crew actually filmed on Mr. Everest. They had no choice but to deal with Mother Nature. They faced cold temperatures, high winds and an unforgiving sun.
But it wasn't as miserable as you might assume.
"If you're not shooting, then you're off on some other adventure with a few other guys because you're up on top of a mountain," says Jake Gyllenhaal, who plays real life climbing group leader Scott Fischer in Everest (in theaters now). "Sitting around isn't the best thing to do…You got to stay warm…When you weren't shooting, you were just adventuring…It was great fun."
He added, "The coolest part of the day was just starting in the morning and gearing up down the mountain. You have all your gear with you…It really doesn't feel like a movie at all."
SPOILER ALERT: Although the movie is based on real events, the following contain details you may not want to know before seeing the film if you're not familiar with the story.
It wasn't such great fun during Gyllenhaal's death scene when someone had to cover his face with his backpack.
Gyllenhaal had filled the backpack with sandbags to give it a realistic look and feel.
"I was laying there in the snow," Gyllenhaal said. "The guy who plays Anatoli [Ingvar Eggert Sigurðsson] took my bag…and he just slams it on my face."
Jason Clarke, who plays a fellow climbing group leader Rob Hall, laughed, "You asked for it…You got it."
Clarke said his "back was a mess" during the end of shooting when they shot on a sound stage in London. "It was a lot of twisting and carrying and hanging off ropes and then blowing salt at us," he said.
Clarke had nightly treatments from masseuses and chiropractors "just to put yourself together for the next day."
Everest also stars Josh Brolin, Keira Knightley, John Hawkes, Robin Wright, Michael Kelly, Sam Worthington and Emily Watson and was directed by Baltasar Kormákur. It's based on Jon Krakauer's bestseller Into Thin Air.