Half a century ago while working in communications in the Army, my coworkers and I were not required to wear our metal dogtags or the chain holding them. If you are working above an operating piece of equipment to repair it, the tags can suddenly fall out of your shirt and into the equipment, providing an excellent path for electrocution. Rubber soled shoes are very helpful but not sufficient.
It was also standard practice to work with only one hand. The other hand would be firmly in one's pants pocket. This would reduce greatly the chances that a deadly current could flow from arm to arm, stopping the heart.
I can remember frequently finding that my pocketed hand would ache at the end of the day from being in the pocket.
Another thing worth noting is that the marketplace, including china, is more than willing to supply sub-standard USB charging devices that presented both a fire hazard and an electrocution hazard. The typical USB charger uses an isolation transformer which should prevent the AC from appearing on the output of the device and the rest of the charger circuit uses optical isolators to prevent dangerous failures. Unfortunately, the sub-standard chargers allowed metal connections to be too close for long-term reliable operation. I know this because I bought some chargers before checking them out sufficiently. I never used them.
It was also standard practice to work with only one hand. The other hand would be firmly in one’s pants pocket. This would reduce greatly the chances that a deadly current could flow from arm to arm, stopping the heart.
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I remember that admonition while doing electrical panel work where you might not be able to turn off power on the panel. With two hands, there is the potential one hand is touching a ground, like the enclosure, when the other hand might make accidental contact with line voltage. Then the shortest path for the current is from one arm, thru the heart, to the other arm.