Don't Mess Around Inside a Plugged-In PC

Frankly I'm surprised this doesn't happen more often: A Chinese student opened his computer's case while it was still powered on; he was reportedly so sweaty (it's hot over there) that he created a short circuit and electrocuted himself when he brushed the PC's wiring with his overly moist leg.

It would appear he did this to prevent the PC from overheating, though it's unclear why the internal fans couldn't keep the computer appropriately chilled. Regardless of the climate, the inside of a computer gets much hotter than the outside air anyway: Even a 20-degree difference in the room shouldn't make that much of a difference to the computer itself, provided fans are running appropriately.

The real error here is in running a computer without the case's panel attached. Turn off your computer and take a look inside. Most of the wiring is insulated, but exposed circuit boards and poorly-seated connectors can be deadly, as proven here. (Another potential danger: Cooling fans that spin at extreme rates. Take it from someone who got a severe gash from getting a knuckle caught in one that they aren't to be trifled with, even though they're made of plastic.)

Here's the right way to get inside your PC: Turn it off, wait for everything to power down completely and all fans to stop spinning, then flip the "off/on" switch on the back of your power supply to off. (This is a small, usually black switch on the upper part of the rear of your case.) Now open the case, then touch a metal part of the case to ground yourself and eliminate any static electricity on your body. Finally, unplug the PC from the wall socket. (You have to do this last, otherwise the grounding step won't work.) Now it's safe to start messing with your computer.

Reverse the steps when you're ready to get it going again, and don't run it with the side panel removed: It's not just dangerous; in a properly designed PC, it can actually make things run hotter by disturbing the usual airflow.

LINK: Sweaty Chinese Man Electrocuted By Computer