Overpressure absorbing material is positioned on the exterior of an enclosure. When an explosion occurs adjacent the enclosure, the overpressure absorbing material absorbs a large portion of an incoming overpressure wave from the explosion. The overpressure absorbing material cushions the impact of the overpressure wave against the enclosure and may prevent the incoming overpressure wave from penetrating the enclosure in sufficient magnitude to cause injury to the enclosure's occupants. The overpressure absorbing material may also be positioned on the interior of the enclosure. The overpressure wave from the explosion may enter the enclosure via a breach or other opening and may resonate within the enclosure, causing injury to the enclosure's occupants. The interior overpressure absorbing material also prevents a significant magnitude of the overpressure wave from being reflected off the interior walls of the enclosure, resonating within the enclosure, and causing injury to the enclosure's occupants.