Damian Lewis has told how he cooled off from his violent character in new film The Silent Storm by jumping into the freezing sea.
The Homeland star plays an erratic church minister in the period drama, set on a remote Scottish island which residents are abandoning in droves to go and live on the mainland.
Lewis was joined by his real wife Helen McCrory and Andrea Riseborough, who plays his wife in the film, at the premiere at the BFI London Film Festival.
Asked about how he wound down after filming emotional scenes, Lewis said getting back to nature in the surrounding countryside played a part.
"Walking up Ben More and some of the other surrounding hills. Went out to sea. We swam quite a lot. People were always stripping off and jumping in the ocean, which was actually lovely," he said.
Lewis also insisted that Hilary Mantel need not worry about the BBC adaptation of her books Wolf Hall and Bring Up The Bodies.
He plays King Henry VIII in the six-part TV drama based on her Booker Prize-winning historical novels.
Mantel recently said that she hoped the series would not reflect the "nonsense" of previous inaccurate historical dramas, saying: "It's perfectly possible to do good history and good drama - they are not mutually contradictory."
"I think she was quite rightly concerned that her books might be abused in some way. However, she needn't worry, because of the people who are involved in this particular project, director Peter Kosminsky is known for his attention to detail and his love of politics," Lewis said.
"This is really a political book, they're not presented as Tudor romps, that's not what she wrote and that's not what we've filmed."
The 43-year-old actor raised eyebrows in the summer, when filming on location at Chastleton House in Oxfordshire, wearing an enormous red codpiece.
"I'm glad to say I didn't suffer from wilting codpiece, and Henry was fully functional at all times, being the slightly, erratic, unpredictable king that he was. A fabulous, fabulous part to play," he said.