Jim Carrey reveals brutal Grinch make-up routine that saw him need anti-torture training

Jim Carrey revealed the CIA gave him anti-torture training during How the Grinch Stole Christmas after he felt 'trapped' in his prosthetics.

There are a number of festive movies which signal that the Christmas period is truly in full swing.

These include the Home Alone franchise, romance-drama The Holiday and, of course, The Grinch.

While people reckon classic 2000s movie is now ruined forever after spotting a mistake, there's another reason you might never be able to watch the Ron Howard-directed movie in the same way again.

While The Grinch's furry, green body and cat-like face make him instantly recognizable, it made Carrey incredibly miserable on-set.

So much so that a CIA specialist had to teach him distraction techniques to mindfully work through the discomfort.

Carrey told Irish TV host Graham Norton all about his ordeal on his late-night chat show in 2014. The actor, now 62, revealed he felt as though he was being 'buried alive' in the heavy Grinch prosthetics.

He explained: “I couldn’t see. I couldn’t breathe. I couldn’t scratch myself. The physical restraints were unbelievable.

"It was just like having a refrigerator strapped to your back."

Its application was time-consuming, taking two-and-a-half hours each day to apply all the green paint, face-altering prosthetics, and then painstakingly stick in the Grinch's hair.

Carrey had wear the make-up for 92 days of shooting, meaning he spent 230 hours - or just more than nine and a half days - sat in the make-up chair.

It then took an hour each evening to remove.

Carrey shared with Norton the advice he took on board to calm his nerves.

“If you’re freaking out and spiraling downward, turn the television on, change a pattern, or have someone you know come up and smack you in the head, punch yourself in the leg, or smoke - smoke as much as you possibly can," he revealed.

He says he also calmed himself by listening to the Bee Gees.

Director Howard himself even spent a day in full Grinch prosthetics to understand exactly how Carrey was feeling.

But it wasn't just Carrey who found the gruelling make-up routine difficult. Make-up artist Kazuhiro Tsuji had to walk away from the project and check into therapy, but eventually returned to the movie once Carrey put his coping techniques into practice.

And after three months of filming, thanks to his CIA training, Carrey had mastered the art of patience.

“By the end, you could literally hit me in the face with a baseball bat and I would have gone… ’Good morning. Nice to see you,'" Carrey said.