Do latex mattresses sleep hot?

Hi Phoenix,

My husband and I are on the quest of finding the perfect mattress for our needs. We are interested in latex due to its comfort, support & durability. Your website has been exceptionally helpful and has answered many of our questions as well as finding local manufacturers in Asheville, NC.
Just need your opinion in regards to Talalay vs. Dunlop…do they sleep warm/hot? We both have a hard time sleeping when hot which is the reason we gave up on memory foam.
We liked a 7" Extra-Firm Talalay at Colton Mattress & will be driving this week to Rocky Mountain Mattress to test their 9" Natural Latex (6" Dunlop core/2" Talalay/1" of pure organic Juma wool).
Which type of latex “breathes” better in your opinion without giving up support?
Any thoughts would be most appreciated.

Thank you,
Alicia

Hi cedarhunter,

In addition to the information in this post … post #29 here has more information about temperature regulation and the microclimate on a mattress.

There are many factors which control the sleeping temperature of a mattress and only one of these is the foam that is used in the mattress … particularly in the upper layers.

There are 3 main types of foam which is memory foam, polyfoam, and latex. Of these three … memory foam tends to be the most insulating and least breathable followed by polyfoam and latex is the most breathable. Talalay tends to be more breathable than Dunlop. There are also variations in each category and less dense foams tend to be more breathable than denser foams while firmer foams tend to allow less sinking in which can mean there is less insulating foam material against your body.

All foams are insulators (rather than heat conductors) so to some degree they will all be warmer than mattresses that contain no foam at all (such as mattresses that only have an innerspring and layers of natural fibers on top) but these tend to be premium or super premium mattresses and for the most part almost all mattresses have some type of foam in the comfort layers.

Some of the other factors involved in how warm a mattress sleeps are how closely the foam conforms to your body (the more closely it conforms around you the more insulating it is), how soft or thick the foam in the comfort layers are (the softer/thicker it is the deeper you will sink into the more insulating materials), the type of quilting used in the mattress (natural fibers allow for more airflow and humidity control which translates into better temperature regulation), the type of ticking (cover) used (natural or more breathable fibers such as cotton or viscose or even some of the more breathable synthetics will wick away moisture and ventilate better and humidity control is a key part of temperature control), and on any cooling technologies used in the mattress such as ventilating and moisture wicking materials, heat conductive materials, or phase change materials (you can read more about these in post #9 here and at the end of post #4 here) and you can read more about the various different types of gel foams in post #2 here. In general terms gel foams will tend to have a temporary effect on temperature while you are first going to sleep until temperatures equalize but have less effect on temperature regulation throughout the course of the night.

While the upper layers of a mattress are the most significant part of temperature and moisture regulation … deeper support components that allow more airflow can also have an effect and so innersprings will also tend to sleep cooler than foam support cores as long as the air can ventilate to the outside of the mattress.

In addition to this … the mattress protector you choose along with your sheets and other bedding and what you wear when you sleep will also have a significant effect on temperature regulation because they can either add to the insulating effect or to the ventilating and moisture wicking effect of your mattress. You can see more about the effect of different mattress protectors in post #89 here. Bedding made from natural fibers or viscose materials (like bamboo) will also tend to be cooler than synthetic fibers and linen sheets along with silk are probably the coolest of all the natural fibers for those where sleeping temperature is a main priority. There is more about sheets and bedding in post #7 here. In many cases changing the mattress protector, sheets, or bedding to cooler versions can make “enough” of a difference for many people who would otherwise sleep hot on a mattress.

All of this of course is separate from any environmental conditions in the bedroom (temperature and humidity levels with higher humidity adding to the perception of heat), on the physiology and tendency of the person themselves to sleep warmer or cooler and where they are in the “oven to iceberg” range, and on their weight and body type which will affect how deeply they sink into the foam layers of the mattress.

In other words … it’s always a combination of several interacting factors that determines the sleeping temperature of a mattress in combination with a specific person and environment.

Overall … if you are looking at a mattress that contains foam of some type … then latex with natural fibers in the quilting (such as wool) and fabrics that can wick away moisture and help it evaporate more rapidly are the coolest sleeping or more accurately the most temperature regulating mattresses and firmer will tend to be cooler than softer.

Mattresses that don’t use any foam at all and only use an innerspring with natural fiber comfort layers will tend to be cooler and more temperature regulating than any type of foam including latex.

All types of latex come in firmer and softer versions which along with the layering (especially the thickness of the comfort layers) will determine how supportive the mattress is and how well it keeps you in alignment in all your sleeping positions. Different types of layering can be more or less suitable for different weights and sleeping positions to balance the competing needs of pressure relief and support/alignment. While Dunlop has a higher compression modulus and will be firmer than Talalay in the same ILD (which is why Dunlop is often used in support layers and Talalay in comfort layers) … both of them can make good choices both in terms of pressure relief and support in appropriate layerings and the choice between them is generally one of preference (they feel and respond differently). This article and post #6 here has more about the different types and blends of latex.

Hope this helps.

Phoenix

Is it possible that the wool makes the mattress feel hotter? We just got a Latex Mattress Factory “Natural” to replace our worn S&F Deacon Ridge and while more supportive, it feels extremely hot.

We ditched the old mattress protector and got a new one which seemed to help a little bit, but not enough.

Had to sleep on top of the covers to avoid the heat last night.

Was thinking of buying a 2" latex topper in cotton to get away from the mattress because I cannot sleep through the night. Is it the wool making the mattress so hot?

In my experience, yes, the only mattress I tried during my search that slept cool was Saavta but it was too firm for me. Tried latex both with and without the wool cover and still slept hot, though this is when I realized I definitely slept better without the wool cover which I found changes the feel of the latex. Decided to stick with latex - with a stretch knit cover instead of the wool, as my back is doing better than it has for a long time, just keeping room much cooler than I normally would.

Thanks, Lorim.

Thinking maybe will get a 2" topper in cotton and put it on top of the mattress, then sheets and see if things are cooler.

If you find something that works please post back as nothing I have tried has helped - mattress pads, sheets, etc. Last purchase was the Nacreous mattress pad and stratus cooling sheets from SlumberCloud which also did not help much, if at all.

Hi again!

I would be surprised if the wool is the culprit in your sleeping hot. Wool is among the best temperature regulating materials … and in combination with cotton which wicks moisture into the wool has one of the best effects on cooling. I would also keep in mind that wool regulates temperature in both directions (it’s used in the desert and also in cold climates because of this) so while it may not feel “cool” … it generally doesn’t feel “hot” either and it also helps to regulate the moisture (which can trap heat) and reduce the perception of temperature that comes from higher humidity levels (similar to how temperatures feel cooler on less humid days than they do on more humid days). It’s interesting to note that perspiration itself is a form of phase change cooling as moisture changes from a liquid into a vapor and absorbs temperature and takes some of the heat away as it disperses. So each layer in a mattress can either add to or detract from the other layers that are involved in the microclimate and their ability to ventilate (add to the dispersal of heat and water vapor) as well as wick moisture and store moisture away from the body is all part of the puzzle.

The fact that removing your previous mattress protector helped reduce the heat leads me to believe this may be more related to the cover materials - Layers that are closer to the top sleeping surface will have the greatest impact upon comfort and sleeping temperature (including any mattress pad, sheets, and linen). I am not sure if you have already read 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.

Latex and cotton are both breathable, temperature regulating materials that would be a good option for a topper. If changing your protector and bedding doesn’t resolve the heat issue and before buying a latex topper, I’d test this combination first by opening your zipper and putting some cotton over the existing latex to see if it makes any difference. I’d also be careful with adding 2" more thickness to your bed as this may impact your spinal alignment and cause back pains down the road. Another temperature-related factor that I’d look at is … how deep of a cradle you sleep in. The deeper you sink … the more body heat is “trapped” under you regardless of the materials used.

Let us know how all these small changes pan out.

Phoenix

@lorim … Have you ever tried alpaca wool & silk products next to your skin? You can read a bit more about Alpaca fiber vs Wool fiber here

Thank you for these amazingly considerate and timely responses.

It’s hard to believe a month has already gone by with the “Naturale” latex mattress from Latex Mattress Factory but here it is and I have considerably less back pain than before, really an amazing difference.

My body has adjusted to all the “heat” but we often are sleeping without so much covering. Eventually we’ll get a different mattress cover we just need to find the right one and see how that affects the temperature.

The only weird thing about sleeping on this all-latex (as opposed to the very firm Sterns and Foster with just an inch of latex on top) is that, as my bride describes it, “It’s like sleeping on top of pudding”. We can feel a lot of movement when the other turns in their sleep. Still, a small price to pay for increased comfort.

If I could do it again I might get a softer mattress. The 2" of soft talalay seems very nice, but being dense I feel the firm dunlop underneath. It isn’t painful, but it doesn’t have a super luxurious feel. That said, I do feel much better rested in the morning than before. I’m waking up earlier and more refreshed, well before my alarm clock. Success.

Any tips on a good, breathable mattress cover are welcome. Thanks again.