In cartoons, it’s pretty easy to tell when somebody’s getting electrocuted: Their skeleton flashes through their skin, their hair sticks straight up, and there’s smoke everywhere, maybe some electric sparks radiating out from their body.

But what actually happens when you’re shocked is much less flashy—and much more dangerous. Technically, and thankfully, most of the cases we call “electrocutions” are actually electric shocks: an electric current running through a body.

The word electrocution comes from a combination of the words “electric” and “execution,” so it was specifically combined to describe death by electric shock. Whether an electric shock becomes an electrocution depends on the nature of the current involved. A current is the flow of electric charge carried by electrons or ions, and our bodies are pretty responsive to them because they use currents all the time.

For example, tiny electric pulses from the movement of ions across membranes are what trigger neurons and allow me to move and be alive and talk to you right now. So when you’re shocked, and a much stronger current passes through your body, the tissues it passes through can overreact to that gush of electricity. In very mild cases, you might only feel a slight tingle in your skin.

But as things ramp up, the current can cause mild to severe burns, muscle contractions, or even seizures, because nerves and muscles are getting overstimulated. The amount of current that’s flowing is measured in amperes, and a current of only 20 milliamps can cause someone to lose control of their diaphragm and stop breathing. And 100 milliamps can stop a heart.

Now, more than 100 milliamps of current run through your phone charger, but touching its live wire won’t kill you—not that I recommend you try it. It’s not deadly because the amount of current in the wire isn’t actually what matters. What matters is how much current gets into your body.

And that’s influenced by two things: the voltage, which is the difference in electrical potential that’s driving the current, and your body’s resistance to the current. Basically, if the current is like water flowing through a pipe, the voltage would be the water pressure, and the resistance would be like the narrowest section of the pipe making it harder for the water to flow through. Your skin is pretty good at resisting current as long as the voltage isn’t too high.

It’s a strong, natural barrier to electric flow because it’s dry and thick. It has way more resistance than the wires in your phone charger, so it experiences much less current. Of course, even when your skin resists the current, the energy from it still has to go somewhere, which is why heat is generated, and why stronger shocks can burn you.

Electricity above 500 volts is considered high voltage, and it’s enough to punch through the resistant barrier of the skin and zap someone with enough current to stop their heart. In some cases, this is actually helpful. If the heart isn’t beating right, the carefully targeted, split-second 3000 volt shock from a defibrillator can act like a reset button, allowing its muscles to fall back into a normal rhythm.

But, in a healthy person, stopping the heart is obviously very, very bad. When skin is damaged or wet, it has much less resistance. That’s why hairdryers have those super strong warnings that using them in the bath can be fatal, even though a typical electric outlet is considered “low voltage”: about 120 volts in the US and 230 volts in Europe.

So even though an electric shock can be mild and relatively harmless, even low voltage power sources can pose significant risks, and high voltage sources are always super dangerous. Which is why you should always be aware of potential shock hazards. And hopefully, you won't ever experience the true definition of electrocution.

Thank you for watching this episode of SciShow! If you really are fascinated by electricity, you might want to check out the episode on whether you can supercharge your brain with batteries over on our sister channel, SciShow Psych at youtube.com/scishowpsych.