Unergarments are clothes worn under other clothes, often next to the skin. They keep outer garments from being soiled by perspiration, shape the body and provide support for parts of it, and in cold climates help the wearer to keep warm. Undergarments can be used to preserve the wearer's modesty, as well as for erotic effect. Special types of undergarments have religious significance. Some items of clothing are designed as underwear, while others such as T-shirts and certain types of shorts are appropriate both as undergarments and as outer clothing. If made of suitable material, some undergarments can serve as nightwear or swimsuits.