Memory Foam was originally developed by NASA in the 1970s, and has since become one of the most popular mattress technologies on the market (who doesn’t want to sleep on space foam?). But seriously, memory foam (or viscose) is a lightweight and comfortable mattress material that offers the highest degree of contour to your body.

Memory foam is temperature sensitive, meaning that it is firmer at lower temperatures and softer (more conforming) at higher temperatures. This accounts for the “melting” sensation and custom moulding effect you feel as you recline on a memory foam mattress.

Memory foam features open cell construction (individual cells with holes). When you lie down, your body weight compresses cells that “share” the pressure with adjoining cells, distributing your body weight over a greater surface, resulting in fewer pressure points and a more comfortable sleep surface.

Memory foam may not be the most supportive mattress, but it does hug your body best. What’s more, it offers practically no motion transfer or lateral movement in the mattress, meaning that your partner can roll around all he or she wants, and you won’t even notice!

Memory foam mattresses are available in different densities and levels of firmness. When you check for density, remember that the fewer air bubbles there are inside the foam, the higher the quality of the mattress. Less air means longer mattress life. Also, you’ll want to look at the IFD, or the Indentation Force Deflection, to know how hard or soft the mattress is: the higher the number, the firmer the mattress.