There was a recent story about an 18 year old girl who consumed a drink made with liquid nitrogen and then had to have her stomach removed in order to save her life.
“Liquid nitrogen has become popular for the making of some elaborate cocktails.
The liquid form of the gas can be used to flash–freeze substances, and some bars use it to chill glasses or freeze ingredients, producing a dramatic–looking grey vapour.
Numerous recipes for liquid nitrogen cocktails can be found on the internet but the substance can cause serious cold burns and should never be ingested.
If liquid nitrogen is added to a liquid such as an ice cream mixture, it cools the liquid rapidly while it boils away and produces a cloud of vapour.
Once the liquid has evaporated back to nitrogen gas it is more or less harmless.”
However, if not prepared properly, “The temperature of the liquid is around -196C and if it is not used properly it can cause frostbite or cryogenic burns” – Professor Peter Barham, of the University of Bristol’s School of Physics