The Leidenfrost effect is demonstrated using some "Mad Science".
To get this effect, I took a deep breath in, held it, then poured a small amount of LN2 into my mouth, and blew it out forcefully without hesitation. Assuming that my mouth is approximately 98.6F and liquid nitrogen is -321F, there is a difference of nearly 420F. As the liquid nitrogen contacts my mouth, it is instantly boiled and vaporized, and amazingly doesn't make contact with my mouth at all. The cloud you see blowing out as a cloud is caused from moisture in the air being condensed by the extreme, and sudden, temperature change. There is a danger if larger amounts of LN2 are used, as it could quickly cool the mouth and cause tissue damage.