I did a 12 month college internship at [link|http://www.smud.org/|SMUD], the Sacramento municipal electric utility. The utility yard I spent a lot of time at was also the training area for linemen. The policy at SMUD was that they worked hot: circuits weren't deactivated. This meant that the linemen were aware at all times that they were one false step from Flaming Yon. You didn't cut a circuit, you bridged it. Saw a few training vids on the topic as well.
There are industry meets where linemen from different utilities do their stuff -- linemen's rodeos. Objective is to complete a task in the least time with least mistakes.
Typical linemen's gloves and boots will give pretty good insulation, dry. There's also the good old "ten foot pole" thing and other stuff.
SMUD's safety record for linework was significantly better than PG&E's, who practiced working dead circuits.