Kate Winslet had nightmares after filming 'The Mountain Between Us'.
The 41-year-old actress - who has kids Mia, 16, and Joe, 13, from past marriages and three-year-old Bear with husband Ned Rocknroll - stars with Idris Elba in the thriller as survivors of a plane crash left stranded on a remote, snowy mountain, and she admitted spending long days in the icy conditions took their toll.
She said: "I would have panic dreams about my children being trapped under ice."
And that isn't the only movie role to have affected the Oscar-winning star's sleep, as she regularly woke up "in sweats" and filled with anxiety while shooting Woody Allen's upcoming film 'Wonder Wheel', in which she plays a woman trapped in an unfulfilling marriage and a dead-end job.
She told New York magazine: "It was the most white-knuckle ride I have ever had in my life.
"I would wake up in the middle of the night, in sweats, about going to work the next day.
"And my hands would hurt -- I had been sleeping with a clenched fist and pressing my nail into my fist. Now that is proper anxiety."
Despite shooting 'The Mountain Between Us' in temperatures of -38 deg C in the Canadian Rockies, Kate admitted the "extreme circumstances" were part of what appealed about the role.
She said: "I'm much more taken by an extreme set of circumstances than an easy, comfortable route. I like a challenge, and it's been a long time since I've done a film that required such a level of physical exertion and stamina and commitment -- and also overcoming a certain degree of fear every single day.
"Plus, I'm a much more cold than hot sort of person. If a script says, 'It's a sweltering hot day on a beach in Tahiti', I'm less interested."