Abstract: A mattress topper for providing improved comfort to a sleeper comprises a pressure distribution layer defining an interior volume. The pressure distribution layer has substantially air-impermeable side walls and a substantially air-impermeable base, and a top surface having at least a region that is air permeable. Support material is contained within the interior volume. The mattress topper includes at least one electrically powered air circulation device for drawing air into the interior volume of the pressure distribution layer via at least one air inlet port. A lateral air-flow layer is disposed above the pressure distribution layer and is configured to provide substantially unimpeded air flow both upwardly and laterally.