The Scoville scale is a measure of the hotness or, more correctly, piquancy of a chili pepper. These fruits of the Capsicum genus contain capsaicin, a chemical compoun which stimulates chemoreceptor nerve endings in the skin, especially the mucous membranes. The number of Scoville heat units (SHU) indicates the amount of capsaicin present. Some hot sauces use their Scoville rating in advertising as a selling point.