Polyurethane (PU) composite foam containing microencapsulated phase change materials (MicroPCMs) was fabricated by adding heat-treated microencapsulated n-octadecane in reactants. The microcapsules are evenly inserted inside the foam. The composite foam absorbs heat energy at approximately 31 degrees C, and releases heat energy at approximately 28 degrees C. The enthalpy of the foam rises with the increase of the content of MicroPCMs. It is above 12J/g for the foam containing 12.59 wt% MicroPCMs. The addition of MicroPCMs has no significant influence to the thermal stability of polyurethane foam. (C) 2008 Elsevier B.V. All rights reserved.