Elemental Mercury isn't especially dangerous though. People freak out over the word "Mercury" but forms like that aren't bioavailable for the most part and are reasonably safe. I wouldn't go breathing the fumes for extended periods of time, but holding a pool in your hand in science class isn't going to kill you.

That's why it's a bit frustrating to read stories like this where the cleanup crew goes overboard and racks up tens of thousands of dollars worth of bills for a simple spill.