Has your student come home with a black square on their arm from a Sharpie? Most likely they've been "shocking" themselves at school. The idea is to get a rush of adrenaline from shocking yourself using a Sharpie and your phone.
How it works: students draw a black square on their arm with a Sharpie. Then they open up the camera on their phone and turn on the flash. You then put the flash of the phone where the Sharpie square is drawn and take a picture. The result is a "shock" to your arm apparently caused by the black marker absorbing sudden heat from the phone flash.
For the most part, there doesn't seem to be anything extremely harmful (except looking like a dummy with a black square on your arm the rest of the day). But at the same time, there's probably not a positive outcome for doing this. Check out the video below as well as some other info and pictures.
Discussion questions with MS students: Have you seen or heard of this being done? What was your reaction? Why did/didn't you do this? What is the point of doing this?