One variant of a fluidizable bed (10) includes a fludizable material (36) within a containment vessel (12) and a filter sheet (24) having a vent region (42) covering a top portion (22) of the vessel. The vent region has a permeability of less than about 65 cubic feet per minute per square foot. Other variants of a fluidizable bed (10) include a fludizable material (36) within a containment vessel (12), a filter sheet (24) connected to the vessel, and a vent region (42) of the filter sheet covering a top portion of the vessel and having a permeability sufficient to 1) establish a pressure difference across the filter sheet equal to or greater than a prescribed pressure difference threshold, or 2) support no more than a specified, non-negligible portion of an occupants weight.
