Helen Hunt was ''totally, completely naked'' when she shot scenes for 'The Sessions'.

The 49-year-old actress portrays a sex surrogate in the new movie and admits she felt ''vulnerable'' when it came to shooting the intimate scenes.

She told the New York Post newspaper: ''This poet had polio at age six. At 37, he's told he won't live much longer. With an iron lung, can only turn his head at a 90-degree angle, he wants to experience sexual life for the first time. That's when a professional sex surrogate is called in.

''I play the sex surrogate. The material created a vulnerability. I personally felt extremely vulnerable.

''No body make-up, because that gets sticky and creepy. So I did it naked. All naked. Butt naked. Totally completely naked. Naked beyond just naked.

''My jaw dropped at the prospect. When I was about to take my clothes off, my palms started to sweat.''

Helen met with the woman she plays in the film and says the struck up an instant connection and she is thrilled the sex surrogate loved the finished movie.

She added: ''It's rare to read such a beautiful story. True story. This real life therapist, living in California, is Cheryl Cohen Greene. Typical soccer mom with a house, mortgage, husband. We met. I stole her spirit. Her accent. She's not shy or filled with shame. She's instantly open. A real deal. I could ask or tell her anything.

''The day we met she quickly jumped into the shower because she had a therapy session due with a 70-year-old man.

''She loved the finished film because she got her message through and said the things she wanted to say.''