It seems that construction workers become very comfortable with heights. They seem to just go about life as usual with little thought for height at which they are working.
Below is a picture of my dad (light shirt) and another fellow in 1924 or 1925 atop the Ben Franklin bridge in Philadelphia. They are just 60 feet above the Delaware River — not nearly as far up in the lunch crew in the famous photo. But whether you fall 60 or 600 feet, you are still dead. Dad is 19 or 20 years old in the photo and an apprentice electrician. The original photo is about 2.5" x 3.5".