I was wondering if part of the reason that latex sleeps cooler than memory foam was that latex has vertical holes in it, where memory foam doesn’t normally have those holes. I know that the memory foam mattress that I have ordered and others I have seen online use vertical holes in the top layer to regulate heat by allowing air to come in and out. And the pictures of latex I have seen also show vertical holes, although my understanding is that the vertical hole in the latex do not go all of the way through the foam like the ones designed to be in memory foam.
Also, as a side note. I popped into a small mattress store the other day just to see if they had a latex mattress on the floor since I have not tried a latex mattress yet and I am curious to try one. They didn’t have any and then the owner told me many times that latex slept really hot and was not popular because of that. I didn’t tell him that all of my research supported that memory foam slept hotter. I just smiled, nodded my head and left.
There is more information about the many variables that can affect temperature regulation in post #2 here (which involves more than just the type of foam in a mattress) but the simple answer is that in general latex is more breathable than memory foam which allows it to transport moisture and heat away from the body more effectively and doesn’t “trap” heat and moisture against the body.
Even if a latex layer was cut from the top or bottom half of the original mold and has pincores that go all the way through it … the vertical holes wouldn’t be as important as the more open cell structure of the latex itself unless there are horizontal channels under the pincore holes that can transport moisture and air away from you through the pincores and into the outside environment because otherwise the holes in the latex would be blocked by any solid foam layers underneath them so the airflow through the pincores would depend on what was underneath them.
While it’s true that some people can sleep hot on any foam mattress because foam isn’t as temperature regulating as natural fibers for example … it would be much less common with latex than with other types of foam and he certainly doesn’t seem to be particularly knowledgeable about mattress materials.
