Photo: Jean Baptiste Lacroix/WireImage.com

About 12 years ago, I went with some friends to celebrate my 40th birthday at a funky resort in Palm Springs. The spa was really old-school and had all these specialized body treatments. I got a salt scrub that was supposed to be followed by 15 minutes in a steam cabinet—a large, coffinlike box that encloses your whole body except your head, which sticks out of a hole at the top. It reminded me of that I Love Lucy episode where Lucy sits in a steam cabinet to lose weight.

I'd had this treatment before with no trouble, but this time I started to feel claustrophobic after about a minute. The woman who'd given me the treatment had left the room, and I began to sweat—more than I was supposed to. I practice yoga and meditate regularly, so I tried to breathe slowly and calm my thoughts. It didn't work. I tried to distract myself by thinking about something pleasant. That didn't work either. The panic was rising. My heart was pounding. I felt trapped.

There's something in me that likes to be self-reliant, so I was too embarrassed to call for someone to let me out. I decided to search for the latch and free myself, only to discover there was no latch to be found. That made it worse—I was locked in and I was freaking out.

I've always had a tendency to let my thoughts run wild. When I took one of my first plane rides as a kid, I convinced myself that we were going to crash. I imagined what it would be like so vividly that I broke out in hives. By the end of the flight, they were all over my body. When we landed safely, the hives went away. As an actor, it's a gift to be able to immerse myself in scenarios that aren't real. As a person, though, it's not so great.

After about five minutes that felt more like five hours, the woman came in to check on me. I casually squeaked, "I'm ready to come out now." And then...she simply opened the door. There had been no latch; I could have gotten out at any time. All I had to do was gently push the door, and I would have been free.

I laughed and thought, "What a perfect 40th birthday present." We all do this—create situations in our minds that aren't real. We think we're trapped when, really, there's always a way out. All my fears, I realized, were in my head.

To this day, whenever I feel trapped in any kind of situation, I remember that steam cabinet. Whether it be a relationship, a work situation, or even sitting in traffic, I remember I have options.

If I catch my thinking mind spinning out of control, I remind myself that there is no latch. All I have to do is gently push the door open, and I'm free.

— As told to Rachel Bertsche