Abstract: A mattress comprising a foam base, a foam core, and a foam comfort layer. The foam core may be reinforced with firmer transverse members selectively placed along the length of the core. The core may also include air passages. The comfort layer may comprise interlocking upper and lower layers configured to form ventilation channels that operate in a bellows-like fashion moving moist, warm out and drawing fresh air in as the sleeping body moves and shifts through the sleep cycle. The ventilation channels in the core and the comfort layer provide for effective dissipation of heat and moisture even from the innermost regions of the mattress. A cooling gel top layer may be included, and the entire assembly may be covered with a fabric top panel and surround. The surround may be vented to facilitate air movement in and out of the mattress.