Use caution when handling these chiles: cayenne peppers are so hot that they can instantly irritate the skin on the hands and it can be excruciating if they come in contact with the eyes. Wear thin disposable surgical gloves while working with hot chiles, and don’t touch your face until the gloves are removed. The seeds and membranes in chile peppers contain most of the capsaicin, the compound that lends them their mouth-searing qualities. Cayennes are mostly used without their seeds and veins. Finely chopped fresh cayenne imparts intense heat to sauces and stews, particularly in Cajun and Indian cooking.