Why do mints make your breath feel cold ?

According to a group of scientists in San Francisco, the reason is that the same nerve fibres that signal hot and cold are also sensitive to menthol, an ingredient in mints. Normally when the temperature changes it causes pores on the surface of the nerve cell to open and close, changing the electrical activity of the cell, which the brain interprets as a change in temperature. But menthol can also affect the function of the pores in the same way and triggers the nerve cell into thinking that the temperature is lower than it is.