Why Memory Cotton Mattress Heats？

memory foam mattress is a specialized type of polyurethane foam design to have properties that are both viscous and elastic in nature, and one of its design characteristics was to absorb the energy of motion (NASA AMES research project). Being a dense material, it has thicker struts (cell walls) and smaller windows (cell openings). The specialized chemical composition does take the heat and "absorbs" it to soften the struts and the feel of the foam - this is part of the design. Additionally, humidity affects the feel of the foam, softening it. Combine this with the smaller windows for lower air flow (cfm), you have a foam that isn't the best at heat transfer.

To minimize this innate characteristic of memory foam mattress of being poor at heat transfer, foam manufacturers have recently come up with different types of the phase changing additives (fillers) to add to the viscoelastic foam, lowering the density and also increasing the rate of heat transfer. Some of these work better than others, but chances are you'll still tend to sleep a bit warmer upon a memory foam mattress. It's simply the nature of the construction and composition of the product.

As far as ways to help minimize the heat-trapping characteristics, make sure you're placing the item upon some sort of a foundation that allows air to circulate under the mattress .