Composite foams having cells containing shape-stabilized phase change material (ss-PCM) particles are described. Composite foams may be made by contacting a plurality of ss-PCM particles and one or more pre-polymer reactants, wherein each ss-PCM particle can form a nucleation site for foam cell generation. The composite foams may be used in regulating the temperature of an article wherein the foam undergoes a phase transition as the surrounding temperature of the article approaches the foam's phase transition temperature. The thermostatic material may exchange heat with the article during the phase transition, resulting in regulation of the temperature of the article. The composite foams may be used as a thermostatic packaging material having a cavity for storing goods.