A visco memory foam mattress gets it's name from the visco-elastic material developed for NASA in the early 1970's in conjunction with the space program.
The astronauts in the space program were facing incredible g-forces, at take-off and re-entry, and the materials that were available, at that time, weren't sufficient to cushion their bodies.
Of course, they weren't looking for a memory foam mattress, they needed seating that was more like a big, overstuffed recliner.
Visco memory foam was developed from foam that had some unique characteristics, such as being open celled and able to return to their original shape and resiliency after being compressed.
You may have seen the commercial with the 30 ton steam roller smashing a mattress flat and how it slowly returns to it's exact original shape...or maybe you're more familiar with the picture of a hand above a mattress with the hand print still showing on it.
Both illustrations are meant to show you the slow recovery of visco memory foam.
Because the billions of cells, in a visco memory foam mattress, are open, air can slowly escape from them and pass into other cells that are adjacent.
As you lie on a visco memory foam mattress, it "melts away" from you until your body is completely and evenly supported over it's entire surface.
That's what has been termed by some as feeling like you're floating in space. (Even though I love my mattress, I've never felt like that was a good explanation of how it feels)
A visco memory foam mattress is temperature sensitive, so it reacts to your body temperature by softening where your body is in contact with the mattress.
If you have an injury, with a fever, the mattress is softer under that place on your body.
In the beginning developments of this material, it was too expensive to be used for residential consumer mattresses and pillows.
Over time, the manufacturing costs have been whittled to a point that a good memory foam mattress is as reasonably priced as a good innerspring mattress and there is no comparison in the comfort of the two.
Memory foam is now being combined with other materials to meet the needs of the vast multitude of consumers who are looking for:
a better night's sleep
relief from back, neck or leg pain
relief from a partner's restless movement
a compromise to a softer feel for one person while maintaining the support the other person is used to from a firm mattress
Schedule some time to do some memory foam mattress pricing comparisons and you'll see that you can, affordably, be sleeping on a mattress that is great for your body, health and your budget.