Why does our tongue stick to a cold metal pole?
The short answer is that the water on your tongue freezes solid between the skin on your tongue and the cold metal. For this to happen the temperature of the metal must be below 32°F (freezing point of water), otherwise the water cannot freeze. The lower the temperature of the metal the quicker your tongue will stick. Even your hand may stick to cold metal if your hand is a little sweaty – like when you pull your hand out of a warm glove. The more thorough answer involves thermal conductivity. Materials that have high thermal conductivity will transfer lots of heat from a higher temperature to a lower temperature. To be exact, the heat conducted away from the higher temperature material (in this case your tongue) to the lower temperature material (the metal) is equal to the product of the thermal conductivity times the temperature difference between the two materials. For the water to freeze on your tongue, heat must be extracted from the water to lower its temperature to the freezing
