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I've always defaulted to the coast guard.  While a lot of the time its just patrol and hanging around those crazy guys might fly 2 hours offshore into a massive storm, 60 kt winds,  at night and then do winch rescues with almost zero reference points while the boat is going up and down 30-40 feet in swells and the pilot is matching the swells to maintain the same height and position. 

After that it falls into utility work but that is such a wide ranging profession that one guy might be working out of a heated hangar and doing power line patrol but someone else is in the bush, fueling out of 55 gal drums and is their own mechanic and having zero support.  I'm still impressed when I see the ones doing the powerline work and having to work with almost zero margin for error.  Thinking about when pulling cables for new transmission lines and working the needle on and off a tower with a hook.