I've been a rock climber, skydiver, tower jockey, appartment top carpenter, tree monkey, cliffdiver, etc.,...
As far as heights go, you can fall off your house deck and land on a step, which will do you in. Actually easier because you weren't wearing safety gear.
You can be wearing safety gear and still get hurt. My back surgery will attest to that. It's you, that is the safest thing you have. Using your head! In creaking trees, in storms on towers, on roofs, at 10' or 1000', using tools, you are your best safety device.
Also... The more you do what you do the easier it gets. The scarier the time that you live through, the calmer you get. And when you are really sure of yourself and the easier the job feels the more dangerous it can become, because you stop thinking about the danger and you can get careless. So, it all boils down to "keep using your head". That's where the fear lives and dies, safety is learned and ignored, and where your nerves are tested and calmed.
Biggest thing we taught rookies: Keep busy and your mind on your work, you won't notice the height, as much! If have some wait time, make sure you take the time to watch a hawk, a babe sunbathing by her pool (I said "wait time" not "work time", get your mind off the girl! -lol-) and enjoy the cool aspects of the job!
Hey? It's just life! Live it!
Just what I've learned, anyway!