Developed under a NASA contract in the 1970s that set out to improve seat cushioning and crash protection for airline pilots and passengers. Memory foam has widespread commercial applications, including mattresses and pillows. It works by becoming soft enough to mold around a person or body shape. This happens when the high-density, low-resilience polyurethane foam reacts to body heat. When the pressured is removed, it returns to its original shape.
Memory foam is often layered on top of foam or a spring unit to provide more support.