Abstract: A medical bed having a frame with a mattress support surface. A mattress having a central portion, which has an upper surface adapted to support a patient's body, and a lower surface to interface with the support surface of the frame. The mattress has a right and a left side bolster disposed on opposite sides of the central portion, each bolster extending above the upper surface. Each bolster defines a recess of reduced bolster height in relation to the upper surface of the central portion of the mattress. The mattress has a mattress cover extending about the central portion and both bolsters, such that the mattress and cover together form a single mattress assembly.