Paying my way thru flight training and college as a mechanic, I was using individual 14”-long feeler-gauges to adjust rocker-arms on a car… While holding the feeler gauge in my left hand I would press the remote-starter switch with my right to rotate the engine to the next valve position to be adjusted. I absent-mindedly laid my left hand (clasping the feelers) down onto the batter….and the long feeler bridged across the open battery terminals…. and immediately became incandescent.
My left palm still shows evidence of that event 52 years later.