Physical Danger
There's danger aplenty in this career. Carpenters get hurt a lot. It's not just the falling-off-a-roof kind of hurt that you have to worry about, either. It's a much smaller hurt—like a wrist sprain or a repetitive stress syndrome kind of hurt where every time you hit the nail on the head.
It's not a good thing. Instead, it sends a nerve-shock up through your spine into that left filling you had dentisted when you were seventeen.
Mess up your body, and you're done. Carpenters with bad wrists can't really do anything except switch careers. How does being an actuary sound?