Oh you don't want to try it now, you say. Well that's probably a good thing because it takes a bit of timing to get this trick right. Really, you don't want your hand in this thing for more than a second because the gas that forms around your hand the moment you submerge it in this all-so-good-vat of freezing liquid dissipates and you're left with no protective barrier.
Video on the jump
(The video from popsci wouldn't work, so I grabbed a video from youtube explaining and demo'ing the effect)
"I hadn’t realized that my hand was quite so deep into the liquid. Amazingly, I barely felt the cold at all. My skin didn’t get hurt for the same reason that water droplets dance on a hot skillet. An insulating layer of steam forms almost instantly between the water and the metal, keeping the droplets relatively cool as they float for several seconds without actually touching the hot surface. To liquid nitrogen, flesh is like that skillet
The phenomenon is called the Leidenfrost effect (after Johann Gottlob Leidenfrost, the doctor who first studied it in 1756). I’d known about it for years, but when it came time to test it in real life, I have to admit that I used my left hand, the one I’d miss less." (Teodore Gray)Thanks to Mr. Gray, he's a testament to all the crazy scientist out there who do cool things!
Via PopSci (Linkage)