Menthol and eucalyptus bind to cold receptors, creating a cold sensation and increasing blood flow and heat generation.

“The point is that compounds from these plants binds to the cold receptor. So as soon as you wrap in your chest, it feels cold, because you sense cold, like the pepper, you feel hot, but that temperature receptor is not only making more energy and whatever but changing the blood flow. So the blood flow increases in this area where you put menthol or eucalyptus and you generate heat.”