While this thread only has 39 replies, I sure hope that a lot more members are reading this thread. Those that have responded have done a good job of explaining the seriousness of this issue.
I would like to add one more note of caution on insulated ladders. Being on an insulated ladder does not give yo u total protection, you can also put yourself in a circuit above that insulated point on a ladder, then you try to become a light bulb from the resistance of your body.
Have been in the power generation and distribution field for 35 years myself, power can and will do some really crazy and amazing things. The 48 volts that was mentioned earlier is enough to possibly reflex wise give you a nose dive of the ladder.