Have you ever wondered why peppermint makes your mouth feel cool? The answer is a chemical compound known as menthol, which tricks your brain into sensing cold. Actually, there are lots of sensory receptors in your mouth containing a protein named TRPM8.
When the temperature of the mouth comes down, TRMP8 acts as an ion channel and allows entry of calcium ions into the nerve cells. This action triggers a neural signal, which is interpreted as temperature fall by the brain. The same procedure occurs in the presence of menthol. Menthol binds to TRPM8 directly and activates it. This way, it gives a sensation of cooling without any fall in temperature.