I have some rather dark humor I would love to apply here, but I think I will pass this time around.
Those kids deserve the harshest punishment possible.
EDIT: Death penalty FTW!
Now before you go and say, "But wait! They are only kids," I should tell you what their victim has to endure.
The victim will have to endure the following:
First, all of the burned portions of his body will begin to swell - causing extreme pain as the burned tissue is stretched tight. Next, he will become EXTREMELY vulnerable to infection as the burned portions of his body have no skin, thus it is FAR easier for infections to take hold. Those infections could attack all of his organs and cause them to shut down one by one. If he's lucky, he will be induced into a coma so he won't have to endure the pain, but that won't stop the infections, the swelling, organ damage/failure, and it won't cure him of the need for extensive skin grafts. The chances of death for extreme burns are pretty good. Even if he is stable for now, chances are he will get pretty damned sick withing the next few days (as the article says).