Memory Foam was invented by NASA in 1966. The idea was to improve the safety of aircraft cushions, but it was not long before the material was developed further and used in more and more products.

Memory Foam is an open cell construction, which reacts to body heat and weight. The more heat applied, the softer the material gets. This, in turn, allows the weight applied to sink deeper. Memory Foam can be made at various densities to result in different tensions/firmnesses. 

The crucial element of Memory Foam is that it softens and moulds to the body shape. This ability allows for very accurate contour support and weight distribution. This ability makes Memory Foam a desirable material for mattresses.

Some mattresses are completely Memory Foam, perhaps using different layers of various densities. Some mattresses use Memory Foam to compliment a Spring Unit.

As Memory Foam requires heat to achieve its desired state, the heat is stored. Some people are not keen on Memory Foam as this heat can gradually build, resulting in a warm bed. However, this stereotype can be seen as outdated, as many manufacturers have solved the issue by applying new techniques to compliment the Foam. Techniques such as Outlast and Coolmax.

Memory Foam is also Hypoallergenic and is therefore very popular with Asthma and Allergy sufferers.