I have this problem. I am never calm in high-stress situations. I'm pretty good in crises that involve other people, especially my loved ones, but when the crisis is mine, I lose all my cool. I'm so envious of people who resemble cucumbers when the going gets tough that I finally decided to get off my duff and learn how to stay cool myself. If you have the same problem, venture forth with me and we shall learn how to lay chilly together.
1. Don't Lose Your Sense of Humor
Humor can diffuse all sorts of high-stress situations. You'll have to judge for yourself if joking around is appropriate in a given situation, but typically, kidding around will keep you calm even if the other people involved don't appreciate it. That's why I stress the importance of being appropriate. This is the reason people in high-pressure jobs – pilots, doctors, police officers, people in the military – often tell ribald jokes in private. When you laugh, it releases hormones that keep you calm and increase your sense of control.