Pursuant to which, what you do want to do is identify efficient de-stressing methods which work for you, and try to train them to be as reflexive as possible. I know it sounds obvious, but it's a valuable type of conditioning which simply doesn't occur to a lot of people.

Personally, I like meditation and biofeedback, since you can do them whenever and wherever, and use them to either tone down your stress enough to function, or try to get a full reset, depending on how much time you have.