There’s not a lot of documentation on this experiment, but what we know is that the unknown liquid is both boiling and freezing. Actually, if you go by the visuals, it seems to rock back and forth between those states quickly. The pressure inside the glass was lowered, which causes the temperature to drop. But it also drops the boiling point of the liquid. Where the freezing point and the new, low-pressure boiling point meet is called its triple point. It’s freaky to watch. I kept waiting for the glass to break, because that just seems like what should happen. -via Viral Viral Videos
(my understanding is that it wouldn't!)
Thermodynamics majors?
Not haxmat stuff but don't bathe in it - you do need some other stuff for the demonstration but Gogle is your friend...