How do you answer this question....

I remember something my lecturer said on my first ever lesson at college on electronics. "Electricity is very friendly, it is only too keen to come out and shake your hand, and then reaches straight for your heart".

Or this one, "it is not the voltage or the wattage that kills you, it is the current, one microamp will make you tingle, one milliamp will cause ventricular fibrillation" (a kind of heart attack where your heart is still intact but locked in spasm and not pumping blood).

Then of course there is the risk from burns.

I think when explaining how dangerous electricity is, there is no sense in dressing it up. Its time to be brutally honest and just tell them, get it wrong and it will hurt your and/or kill you.

Oh, I've just remembered the most fascinating hazard I remember from studying electronics. The "PD burn" (PD = Potential Difference = Voltage). Kind of like a mini lightning strike. Its a widely accepted myth that electricity is exempt from the laws of gravity and inertia. It is widely and incorrectly believed that electricity will always take the path of least electrical resistance even if that involves sharp turns. A PD burn goes like this. You touch just one side of a very high voltage (ie positive or negative but not both). You then instantly become charged at the same potential difference, which in its self is harmless because voltage doesn't kill, but, given the chance an electric arc forms between you and anything of lesser charge (eg the air). You get a very, very brief pulse of current as the arc forms and discharges. Say its your finger that touches the charge and your arm is straight. You get a tiny little shock in your finger tip, like a static discharge, but because the air around you is higher resistance than you are, that brief burst of current fans out at the surface where it meets the air, so you get a burn in your shoulder. Then for days, your whole arm aches for no obvious reason, because it has a tiny, perfectly straight burn running all the way through it, too fine for any kind of scan to reveal, but there nonetheless. As though someone has threaded a needle all the way through from finger tip to shoulder.

If you wanted to dress it up, you could always use the explanation that my physics teacher at school used. Electricity IS fire. There is no difference. (there actually isn't, electricity happens when atoms get 'excited' and electrons start breaking free of their atom and jumping to neighbouring atoms, releasing photons (heat and light) when they do, the only difference between that and fire is that the direction of the flow is controlled).

 

"It's Volts that jolts. It's mills that kills".
When I worked on high voltage stuff, standard procedure was to stand on one leg and use the arm on the same side when first investigating. That way if you got a hit it was less likely to stop your heart by crossing your body. At least that was the theory! I still do this when working on radio gear and domestic wiring.
When working on high voltage switchgear ( and that was 550V to 3.5kV) we always chucked a spanner in first just to check that it wasn't still live!