© 2004 Emerald Group Publishing Limited.Phase change materials have been a main topic in research for the last 20 years. They have also been used in many engineering applications, especially in the fields of thermal storage and insulation. They are used for ice storage, building applications, in the field of solarenergy storage, heat pumps, heat distribution systems, air conditioning, green houses, solar collectors and cookers, for improving thermal comfort in vehicles, and for the conservation and transport of temperature-sensitive materials such as electronic materials, food, the transport of medical tissue, and engines or hydraulic machines. Recently, PCMs (Phase Change Materials) have entered the textile market for use in increasing the thermal comfort of garments. In such extreme applications of textiles as diving suits, ski wear, and underwear, PCMs can impart outstanding properties to garments. Their insulating properties may prevent the wearer from fatal consequences. In this paper, the use of PCMs, methods of evaluation, and methods and areas of application in textiles are discussed.