heathrow director
you are in a relatively comfortable seat, breathing 8000 foot oxygen, and the sun is shining in your cockpit making it warm. you can't move, that breaks the regs.
you fall asleep if you haven't gotten a good nights sleep that's ap ilots lot
an emergency room doctor is moving between patients every few minutes, breathing the same oxygen as where he lives. he looks people in the eye and doesn't focus at infinity.
they are very different animals.