One of the biggest complaints people have against their memory foam mattress is that it gets too hot. But not all beds are created equal. Due the subtle differences in chemical composition, some foam beds stay cooler than others.
The main reason that foam mattresses can get warm is that they are designed to put your body in as close contact as possible with the foam. Foam functions optimally when you are in direct contact with it. The more layers you have between you and the foam, the less effective the foam will be. However foam is also a good insulator, so getting closer creates a better feel but also means the sleep experience will be a little warmer.
Innerspring beds, and many all foam beds, have a layer of polyester fiber just beneath the ticking and above the foam. This layer of filling forms a thin barrier between you and the foam, and does an excellent job of dispersing the heat from your body. But most memory foam beds do not have a fiber layer. Their cotton cover lies directly over top of the memory foam. So it's left entirely up to the foam to disperse heat from your body.
Memory foam is an open cell structure material, meaning that its cell walls are open. The open cell structure allows foam to collapse to absorb body weight and expand to provide support. It also allows heat to flow away from your body while you sleep. And this is the thing that either makes a foam bed hot or not. How well does the memory foam in your bed disperse heat? Different bed manufacturers use different foam, so the only way to really know if a bed is going to be too hot for you is to sleep on it.
How Does a Memory Foam Mattress Compare to Your Bed?
If you have ever slept on an innerspring mattress with 2" - 3" of foam, or a foam bed topper, then you may already have your answer to whether or not a memory foam mattress will be too hot for you. Most innerspring beds today have 2" - 3" of foam on top. This amount of foam will be similar to the warmth of an all foam bed.
So if you feel comfortable sleeping on an innerspring bed with a top layer of foam or a foam topper, then you will most likely feel comfortable sleeping on a memory foam mattress.
Easy Solution for a Hot Memory Foam Mattress
But what if you get a bed and decide that it's too hot, but you really love the feel? Well luckily there is a very simple solution. Mattress pads have a thin layer of polyester filling that will provide an extra layer of cool airflow between you and the memory foam. Simply purchase a mattress pad and put it over the bed, under your fitted sheet. This will draft heat away from your body before it begins to build up in the memory foam.