Linemen used to do what they called the "Smoke Test" on power lines. Even if they were supposed to be de-energized the proceedure was to quickly brush the line with the back of the hand in a slapping motion. If you touched the line palm side and it was hot the muscle contraction would likely latch you on until well done. Where as a glancing brush with the back of the hand might only get you 3rd degree burns. This technique was taught in safety meetings!
