A heat formable patient positioning cushion is provided including an impermeable or permeable outer shell; a filler material contained within an interior region defined by the outer shell; and a thermoplastic material applied to the outer shell, to the filler material, or to the outer shell and the filler material. The cushion has a first condition configured to be conformed to the anatomy of a patient in which the filler material moves relatively freely within the interior region defined by the outer shell, and a second condition conformed to the anatomy of the patient in which the filler material is relatively fixed against movement within the interior region defined by the outer shell. Heating and cooling changes the cushion from the first condition to the second condition and reheating permits increased movement of the filler material as compared to the second condition to further conform the cushion to the anatomy of the patient.