Compounding the misfortune of these and similar tragedies is the fact that many probably could have been prevented. How to protect yourself Winter is the worst time for domestic and industrial electrical accidents, primarily because of wet conditions. The combination of moisture and electricity can be lethal. Electric shock of any sort, even as low as 5 volts or what some Christmas tree lights conduct, can cause heart arrest. Even though most underground electrical lines are marked, some are not.
Visible wires are equally unsafe.
Contrary to popular belief, the vast majority of high-power wires are not insulated, although they sometimes have a very thin coating to prevent weather wear. But that coating is easily arced. Special care should be taken whenever you're close to these wires. Tree trimming or removing wet leaves from the roof, for example, can be hazardous. The minimum safe distance for any object, plant or person from the least powerful overhead lines is 10 feet.