Why do we experience a cold sensation in our mouth or nose when eating or inhaling menthol?

Steve Gisselbrecht, Boston, Massachusetts, US

We feel the cold sensation for essentially the same reason we get a burning feeling when we eat capsaicin, the “hot” in chillies. We have evolved nerve cells that sense heat, which help us know what not to touch, and they use proteins in their membranes that change shape in response to temperature.

Menthol binds to the cold receptor protein and activates it in the same way cold would, just as capsaicin binds to and activates the hot receptor protein. Since our experience of cold is our brain receiving the message that these neurons have been activated, the feeling from menthol is identical to the feeling of actual cold. Plants that could make animals think they were too hot or cold to eat were less likely to be eaten, so there was evolutionary pressure to make such chemicals.


David Cox, CSIRO Health and Biosecurity, Adelaide, Australia

We sense “cooling” menthol with our trigeminal nerve, found in the oral and nasal cavity. This nerve also senses pungency and heat from foods like chillies and the “tingle” of carbonated drinks.

The trigeminal nerve transmits pain, tactile and thermal sensations. It is the latter that gives menthol’s cooling feeling. But menthol is complex and can also be sensed as warming and aromatic depending on the conditions and concentration.

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