Why do chili peppers taste hot but mint feels cold?

It is one of the most curious facts about food: a chili pepper can make your mouth feel like it is burning, while a mint leaf can make your mouth feel refreshingly cold. Yet neither food actually changes the temperature of your mouth. A chili straight from the fridge still feels fiery, and mint does not lower your body temperature at all. So how can food create such powerful feelings of hot and cold without any real change in temperature? The answer lies in a clever trick played on your nervous system.

Your mouth and skin are full of tiny nerve receptors whose job is to detect temperature. Some of these receptors specialize in sensing heat, and others specialize in sensing cold. When you touch something genuinely hot or cold, the right receptor activates and sends a signal to your brain, which you experience as a feeling of warmth or coolness. These receptors are essential for survival, warning you away from things that could burn or freeze you. The surprising part is that certain chemicals in food can activate these very same receptors.

Chili peppers contain a chemical called capsaicin. Capsaicin happens to bind to a receptor known as TRPV1, which is the receptor that normally detects genuine heat. When capsaicin activates TRPV1, the receptor sends the same signal it would send if your mouth were actually touching something hot. Your brain cannot tell the difference, so it interprets the chili as burning heat. This is why spicy food feels fiery and can even make you sweat, as your body responds to a heat threat that does not really exist.

Mint works in the opposite direction using the same principle. Mint contains a chemical called menthol, and menthol binds to a different receptor known as TRPM8, which normally detects cold temperatures. When menthol activates TRPM8, it sends your brain the same signal it would receive from genuine cold. Your brain interprets this as a cool, refreshing sensation, even though nothing in your mouth has actually become colder. So chili and mint are really two sides of the same coin: both are chemicals that fool your temperature receptors, one mimicking heat and the other mimicking cold.

This article was written using information from Wikipedia.