I did a lot of very risky things in the lab after everyone left, some involving liquified gasses, big lasers, big thyratron-switched power supplies, big low-inductance capacitor banks, huge electromagnets, acetylene torches, muffle furnaces, abrasive cut-off wheels, 50K rpm centrifuges, anechoic chambers, molten metal, molten salt baths, induction heaters... came through it fine, and no one found out. On one or two occasions, a wee bit of spectroscopic-grade C
2H
5OH was involved as well.
I never, in my wildest moment of off-the-wallness, ever for one second contemplated putting liquid nitrogen in my mouth. I had it soaked up to the calves of my jeans once though, although that situation didn't last very long.