The Leidenfrost effect happens when liquids boil and create a gaseous barrier between the liquid and the surface it’s boiling on.
This can be seen when very cool liquids, such as liquid nitrogen, come into contact with room temperature surfaces…
and also when room temperature liquids come into contact with very hot surfaces.
As the liquid hits the surface it boils instantly and gas is forced out of the bottom of the droplet, elevating it above the surface. This prevents the transfer of heat between the two.
To find out more about the Leidenfrost effect watch the video