Why do life-threatening situations make some people more calm?

I know personally speaking - when I'm doing something in which I could die if I screw up...I tend to be focused like a laser beam.

bc, one gains a higher tolerance level of fear. and that person is doing what they like. it is like living life, one struggles thru the pains and learn from trials and tribulations.

It seems that when you face something that you've trained for your whole career that muscle memory takes over. I came to terms with the fact that I could die in the line of duty and then I could focus on the problem rather than "Maybe today is the day". I can't speak for the rest of the EOD community, but being in the death business has the opposite affect then most people would have. Capt America doesn't have the smooth nerves that an EOD tech would have dealing with IEDs! ;-) LOL