Just being in a high stress environment doesn't avoid the basic problem of reverting to training in extremely urgent situations. And when said training doesn't exist most people don't perform very well. It goes both ways--my wife is not one that fares well under stress, but one day she dislocated her finger. To her own amazement she calmly put it back--because she knew how and it's something she had experience with doing for others.

Fire drills are about ensuring everyone knows what to do, they aren't done enough to make people revert to training when there's a fire.