Systems and apparatuses include a mattress assembly including a tub including vertically extending rails and a base that defines a base height that is two inches or less, the tub defining an interior cavity bound by the rails and the base, a plurality of non-laminated and rearrangeable foam layers positioned within the interior cavity to provide both support and comfort levels within the mattress assembly, and a cover system that includes a removable cover allowing selective access to the plurality of layers and the interior cavity and selectively compressing the plurality of layers within the tub.