Memory foam was developed in 1966 under a contract by NASA’s Ames Research Center to improve the safety of aircraft cushions and it is now being used in Silent night mattresses. Memory foam is polyurethane with additional chemicals increasing its viscosity and density. It is often referred to as visco-elastic polyurethane foam. It is firmer and cooler than an average mattress.
Higher density memory foam reacts to body heat, allowing it to mould to a warm human body in a few minutes. A lower density memory foam is pressure-sensitive and moulds quickly to the shape of the body. A memory foam mattress is usually denser than other foam mattresses. This makes it more supportive but also heavier. It is often seen as a good compromise between the comfort of a soft mattress and the support of a firm one.
Memory foam mattresses appeal to people suffering from sleep problems and for home owners who desire opulence and comfort in the bedroom.