It appears that when i put a Slurpee in a thermos it freezes?

Question

How is it possible that it actually gets colder?

Answer 1

It's not that it gets colder. What happens is that when a slurpee is made, it consists of lots of additives (mainly sugar). When it is refrigerated, the temperature actually drops to below 0C (32F). The agitation from the machine keeps it "slushy". When you put it into a thermos, it is no longer being agitated, but is still crazy cold. Hence, it freezes solid. This happens to a smaller extent when you are drinking the thing. Notice how you kinda get a "block" of ice in your cup? And that's even on a hot day!