If I have a 3"Latex comfort layer, will the core impact how warm it sleeps?

Hi Edgar!

I’m glad that Post #3 on foam support cores vs pocket coil cores was useful for you.

Without quoting your entire post back to you, that you like many people are sleeping hot on memory foam and are wondering how hot a mattress will sleep depending on the core and that you’re considering pocket coils, polyfoam cores, and latex.

It’s probably no surprise to learn that support layers that are further away from you in terms of mattress layers may not contribute that much to the temperature regulating properties of the overall mattress. The layers that are closer to the top sleeping surface (comfort layers) will have the greatest impact upon comfort and sleeping temperature (including any mattress pad, sheets, and linen).

I am not sure if you have come across some of our posts that discuss temperature regulations issues, but you can read more about the many variables that can affect the sleeping temperature of a mattress or sleeping system in post #2 here more about tracking mattress temperature regulation issues potential causes ~ Post #2 here (at least to the degree possible for a specific mattress) and the posts it links to that may be helpful. You may also be interested in the information in post #29 about temperature regulation and mattress microclimate.

If all else is equal, in theory, spring will sleep cooler than all foams but again it depends how far down into the mattress is. While the upper layers of a mattress are the most significant part of temperature and moisture regulation as it relates to the sleeper, the airflow and ventilation will occur from all sides of the mattress including the deeper support components. A hybrid latex mattress that is using a pocket coil core is one of the most breathable types of cores… followed closely by latex, which is the most breathable and “temperature neutral” of all the different types of foam materials. Latex allows for more airflow than any other foams and when changing positions on the mattress the air will be moved in and out like within an accordion.
Latex is the most breathable foam material and a good choice for those who tend to “sleep hot.” And, to your point, (and as Sensei mentioned to you in post #3 here) mattresses that don’t use any foam at all and only use an innerspring with latex or natural fiber comfort layers will tend to be cooler and more temperature-regulating than any other materials.

It depends on the type of fiber … natural fibers that have more air pockets that allow for the air to circulate would be more breathable and generally are the most effective in terms of wicking and or storing moisture because synthetic fibers generally absorb moisture into the spaces, not the fiber itself. Artificial or “semi-synthetic” fibers (in between natural and synthetic) such as various types of cellulosic or rayon fibers (made from dissolved plant cellulose) are closer to natural fibers and also do a good job of wicking moisture away from the body and ventilating… synthetic fibers would have the most temperature-regulating issues. There are some types of synthetic fibers that are designed to draw moisture away from the skin and disperse it to the rest of the layer that can be effective as well but if the effect is diminished the deeper the layer is within the mattress.

I hope this helps offer some guidance and direction with the sleeping microclimate and choice of mattress materials. Let us know if you have additional questions … it is a bit of a complex issue and everyone is different.