A glove is a garment covering the hand. Gloves have separate sheaths or openings for each finger and the thumb. Fingerless gloves with one large opening rather than individual openings for each finger are sometimes called gauntlets. Gloves which cover the entire hand but do not have separate finger openings or sheaths are called mittens. Mittens are warmer than gloves made of the same material because fingers maintain their warmth better when they are in contact with each other. Reduced surface area reduces heat loss.