Do tongues actually stick to frozen metal?

While it is a common belief, tongues do not actually stick to frozen metal due to the phenomenon known as "cold metal adhesion." While it is possible for exposed skin or moisture on the tongue to momentarily stick to extremely cold surfaces, this occurrence is not caused by the tongue's "sticking" capability but rather by the interaction between water and the cold metal.

When a warm and wet tongue comes into contact with a sub-freezing metal surface, the thin layer of water on the tongue's surface quickly freezes, forming a thin layer of ice that temporarily bonds the tongue to the metal. However, this attachment is weak as it solely relies on the tiny contact surface between the ice and metal. As soon as a slight pressure or movement is applied, the ice layer breaks, and the tongue's moisture acts as a lubricant, facilitating the separation from the metal.

Factors like the temperature of the metal, the amount of moisture present, and the pressure exerted all contribute to the temporary adherence. Nonetheless, it's crucial to exercise caution when touching cold metallic surfaces, especially with exposed skin or moist body parts, as the initial, strong attachment can often be surprising and painful.