Our question for today is:
Will a lower density foam or higher density foam be hotter to sleep on?
Boy, that is a tough question. I can’t say I have a definitive answer for you. We’ve tested a lot of memory foams, and talked with many manufacturers about this issue, but I’ve never heard that density is the issue here. Instead, I think that it is more dependant on the particular characteristics of that memory foam.
What do I mean by this? There are a lot of factors that go into making a memory foam besides the density. There is the particular chemical formulation of the foam, whether any fillers are used (we don’t carry foam that uses fillers, since they are just a way to boost density artificially, but we hear that many memory foams do use fillers like sand, etc to increase density – and these may affect how hot the foam sleeps), and the actual production method for making the foam.
All these may affect whether the foam sleeps hot. And while some of these factors may affect density, I’ve never heard or experienced any sort of hard and fast rule that the density of a memory foam in itself will have some affect on how hot the memory foam sleeps.
In our experience, we’ve carried memory foams with densities from 3.2 lb to over 5 lb. And we haven’t seen that the density really predicted whether the foam would sleep hot. We really never have any heat complaints on either our 10″ memory foam mattress (which uses 3.2 and 3.4 lb density memory foam) or our memory foam mattress topper pads (which use 4 lb density memory foam). In fact, the only time we’ve really run into heat problems was when we used to carry the “leading brand” memory foam mattress. And this really wasn’t a true heat issue – for the most part, it was not due to the memory foam but instead due to the cover they used (which had a plastic sort of membrane to keep your body’s moisture out of the mattress). When we had people remove the cover and just sleep on the “leading brand” foam mattress, almost always they no longer felt uncomfortably warm on the mattress.