A mattress is a piece of bedding used for sleeping. Memory foam mattresses are special types of mattresses that are pressure and temperature sensitive. The origin of memory foam mattresses took place in a very grand manner. In the 70's NASA was working on manned rockets. Manned rockets exert a lot of G-force on the astronauts, which can harm the astronaut. NASA scientists were trying to develop a material that was breathable and molded itself to the astronaut's body to reduce the G-forces on the astronaut. They developed a polyurethane foam material which had the property of visco-elasticity and which could be used for the purpose. Though polyurethane foam was never used in the space program, it got to be used in beddings and pillows later.

Matter is classified into three states solid, liquid and gases. Visco elastic materials are materials that exhibit the properties of both solids and liquids. Polyurethane foam is used in memory foam mattresses due to its property of visco-elasticity. Memory foam mattresses are able to distribute pressure evenly and are able to return to their original shape when the pressure is removed. Memory foam mattresses shape themselves according to pressure and temperature of the person's body to provide support and softness.

Mattresses are either soft or firm. There are 3 positions in which humans sleep;- back, stomach and side. People use more than one position to sleep. Firm mattresses are recommended for people sleeping on back and stomach, as soft mattresses might harm their backs due to unnatural angles. For those sleeping on sides, softer mattresses are recommended. Memory foam mattresses are a compromise of both firm and soft mattresses. They are suitable for all people. The memory foam mattress manufacturers claim that sleeping on a memory foam mattress feels like sleeping on a cloud.

Memory foam mattresses are recommended for people having back problems, arthritis, bone and joint problems, spondylitis etc. Studies have shown that people sleep better on a memory foam mattress. They are available in lots of sizes like, single, double, queen, king, California queen, California king and super king sizes. Some double memory foam mattresses have a softer side and a firmer side to suit the needs of sleeping partners. The usual thickness of memory foam mattresses is 5 inches. Some mattresses use memory foam padding on the upper layer one to two inches thick on the regular mattresses.

Memory foam mattresses begin at around 500$ and are available up to 2000$. Before buying a mattress, it is recommended that the buyer tests by lying on the mattress for at least 10 minutes. Lie on the back. If your finger passes through the small of the back very easily, then the mattress is too firm. If there is no space then the mattress is too soft. If turning around on the mattress is difficult that means the mattress is too soft. The softness and firmness of the mattress depends upon the density of the foam used in the mattress. As the density of the mattress increases the price also increases. As almost one third of our life is spent sleeping, it is better to invest in a good memory foam mattress.