Emma Thompson "pulled every single muscle in her body" shooting her new action thriller The Dead of Winter. In her latest movie, the British actress plays a widowed fisherwoman who interrupts the kidnapping of a teenage girl while travelling alone through the snowbound wilderness of northern Minnesota. Miles away from the nearest town and with no phone service, she becomes the young girl's only hope. During a press conference at the Locarno Film Festival in Switzerland on Friday, the Love Actually star opened up about the physical challenge of playing "a real heroine" at the age of 66. "Why star in an action thing when you're 66?! That's just stupid," Thompson joked, according to The Hollywood Reporter. "The one thing that really scared me, genuinely scared me, was not running about, although I did pull every single muscle in my body, but holding my breath underwater." The Oscar-winning star noted that she tried to get into the best physical shape possible to prepare for both the action scenes and filming in such a harsh, snowy landscape. She added, "We spent a long time getting spent a long time getting used to the cold" in Finland, where they shot the movie. The Dead of Winter also stars Judy Greer, Laurel Marsden as the kidnap victim, and Thompson's daughter Gaia Wise as a younger version of her character. The Sense and Sensibility actress will be honoured with the Leopard Club Award in recognition of her career achievements before the film's world premiere on Friday evening. The Dead of Winter will be released in the U.S. on 26 September.