Question: Why does a person's tongue stick to metal in cold weather?

Arttu Rajantie answered on 13 Jun 2011:

I know this phenomenon too well, because I grew up in Finland where temperature is below zero for almost half of the year. Of course every child has to try this before they believe their parents’ warnings.

The reason the tongue sticks to the metal is that metals conduct heat extremely well, and better than your tongue. When you touch a non-metallic object with your tongue, the parts of the object that are in contact with it quickly heat up above zero because your tongue is warm. In contrast, when you touch a large metallic object, the heat from your tongue spreads evenly over the whole object. Therefore it is not enough to raise the temperature above zero, and instead the saliva on your tongue freezes and sticks to the metal.

If you haven’t experienced this yourself, I wouldn’t recommend trying. It is surprisingly painful and difficult to pull your tongue off the metal. The best way to do it is to pour some warm water on it, so that it melts.