Abstract: The present invention is of foam mattress constructions made and engineered foams which contain additives for improved mechanical and thermal properties. In accordance with one aspect of the disclosure and inventions, there is provided engineered foam for use as a layer in a foam mattress construction having multiple layers including a top layer of foam and at least one additional layer of foam, and a coating of phase change material applied to a top surface of the top layer of foam. Surface application of phase change material to a top surface of a top layer of foam of a foam mattress provides more efficient transfer of heat away from a body on the mattress and reduced heat accumulation at the body-mattress interface.