Skin

The reason many exotic foods taste spicy is because they contain the compound, capsaicin. Capsaicin is found in varying concentrations in several kinds of hot peppers. When capsaicin binds to capsaicin-specific receptors on the trigeminal nerve endings in your tongue and elsewhere in the oral cavity, the nerves send a message to the brain that is interpreted as "hot." This chemical sensation of spicy hot is qualitatively distinct from the thermal "hot" sensation one perceives when ingesting heated foods or fluids.