Leidenfrost effect is the formation of a gas barrier between a hot
surface and a boiling liquid if the temperature difference is great
enough. This gas barrier greatly slows the heat transfer between the
two and allows the liquid to last longer and consequently the hot
surface to remain hot longer. This effect can be seen in a frying pan
as it's being heated. At first the water quickly boils as it's dropped
in but at a hot enough temperature the Leidenfrost effect takes over
and makes the water skate around the surface lasting a very long time.
Liquid nitrogen vs. a room temperature object will also exhibit the effect preventing it from instantly freezing the object... such as my hand.