That feeling of coolness isn't just in your mind; in fact, you're going mental over menthol--a powerful essential oil in mint. Menthol acts as an anesthetic, which puts it in the same category as novocaine and laughing gas. Anesthetics can muffle your nerve endings' ability to detect pain without making you lose consciousness. Other essential oils have a similar effect on people. For example, oil of clove can help reduce minor pain in certain areas of the body and was once prescribed by dentists to soothe toothaches and sore gums. But you won't see dentists giving Pep-O-Mint Lifesavers to patients in need of root canal!
That's because the menthol in your candy is just a very mild anesthetic that acts on nerve endings in your mouth. Some of these nerve endings act as hot receptors, while others detect things that are cold. Since mint oils have the ability to put your mouth's hot receptors to sleep by making them less sensitive to heat, the signals normally sent to the brain by your cold receptors start to stand out a lot more in comparison. The brain then interprets these signals as a cold sensation. (Talk about being in mint condition!) So the next time you hear people in commercials singing about the "cool and refreshing" taste of their mint candies, you'll know they're not kidding!