uhmm, no. I'm sorry but you are wrong. We definately played with a bunch at the end of my senior year after APs outside, and I held it for probably aroun3 second before it got scary cold, but I didn't burn myself. We threw it around like hot potatoe with teacher supervision, that was fun. Then he allowed us to make a bomb out of 2 pop bottles, one with not too much dry ice and water. It didn't blow up, just ripped the side. And the second much more powerful, threw the bottle up 15 feet into the air and made a noise similar to a shotgun, the principles ran out, and everyone laughed. The whole school was talking about 5th period Calc BC's shindig for a while.
But if you're going to make one, don't overload cuase they can be really dangerous.