Actress Olivia Wilde braved the threat of hypothermia on her 28th birthday to shoot new movie Deadfall in freezing Canada, wearing nothing but a party dress.

The Cowboys & Aliens star plays a scantily-clad casino robber stranded in the wintry wilderness following a car crash in the film, which was shot in Montreal, Quebec, and she admits the freezing temperatures were hard to contend with.

She tells the New York Daily News, "I've never been so cold in my life. I was in a tiny sparkly mini-dress made of dust, and it was absolutely freezing. There was a point where I actually thought - and this might just be me being dramatic - that I was getting hypothermia... But the crew was very kind and took care of me when they saw me turning blue."

Director Stefan Ruzowitzky admits Wilde certainly had it tough, adding, "(Co-star Eric Bana) could wear long johns under his suit, but you can't hide long johns under a miniskirt."

And Wilde tells Wenn her birthday was a particularly miserable day on-set for her: "There was a moment where I was hanging upside down in the car in the snowbank after the car crash - and it was my birthday. That was probably the most painful physical experience I've had but it was also a chance to win the respect of the crew because after that they were like, 'Alright, she's tough'.

"I was shivering and spasming from hypothermia so it helped not having to fake it for the scene. I knew what I signed up for; it said in the script that it was freezing, she's in appropriately small clothing in heels in the snow but it was still a shock for some reason."