Although I’ve never sIept on memory foam, I am considering getting a mattress topper made from that material. However, two characteristics frequently cited by purchasers on Amazon concern me: heat retention, and “sink in.”
It seems to me as if both problems could be minimized by putting a padded, “cooling” mattress cover over the topper. Since those would provide insulation from the topper, via air and the characteristics of the fill material, the amount of body heat reaching the topper should be substantially reduced. Since it is that body heat which is mainly responsible for sinking down into the material, and generating the heat which the material retains, it would seem that using a cover–or any DYI cloth items like towels–should substantially lessen the probability of being affected by either of these characteristics.
I’d appreciate it if anyone who has had any experience with making such an attempt would share the results with me. Further, if anyone has a theoretical explanation about whether or not this should work, even though they’ve never tried such an experiment, I’d like to hear about that as well.
The sinking in and heat retention are actually related. Memory foam cells collapse under heat and as you sleep, the heat gets trapped between your body and the foam continues to collapse as the night progresses. The deeper you sink into the foam, the more heat is retained between you and the foam.
I agree that some sort of cooling cover may help. I hope someone who has tried this experiment actively gives feedback!
This is largely correct, and a trade off situation. I like firmer type memory foam in a topper, 5lb density or higher, eg tempur-pedic type memory foam for my top comfort layer (generally I like 4 inches of comfort layer)…
You can even put 2 covers on to further reduce heat. However the downside of covers is that it then reduces the feel of the memory foam and the heat/ responsiveness of the support. For example, if I use no cover at all, and just literally put a bedsheet on top of the foam, then I get maximal soft memory foam feel, and it maximizes the effect of the foam softening just under your body and giving you the supportive cocoon effect feel. The more covers you put on, the less heat responsive the compression of the foam is, and it can feel more like a regular non-memory foam then. For example, if I lie on my bed when its fully made, with quilt and bedspread on, then you dont get the full memory foam feel to the bed. It is relatively more firm of a feel. My memory foam is >5lb density and pretty firm overall, so I really need some of the heat activation for it to feel comfortable and soft. without the heat activation it feels a bit too firm.
this can also vary depending on the season, mine feels firmer overall in the winter when room temperature is cooler.
Thanks very much for your reply. I feel very fortunate that you saw my post, and chose to reply, particularly since your experience confirms my theory.
Thank you also for posting the link to the Zen Bamboo mattress cover on Amazon. It has been very well reviewed, but is not available until July 13. Now that I know that covers will reduce heat retention, I’m interested in getting something that will also add additional padding over a 2" memory foam topper. I realize that in your setup the insulation provided by the covers makes your mattress feel firmer, but have you liked any in the past about which, if that were not a concern, you could say that it added additional padding, and also made you sleep cooler because it added airflow (rather than because it prevented your body heat from softening the foam)?
so right now I am using the Zen bamboo cover. Even though it takes away from the nice “sinking in” feeling of the memory foam a bit, it is worth it to keep cooler in the summer. The cover itself does add a little bit of cushioning. It is about 1/4 to 1/2 in thick of fluffiness, so that gives a slight bit of extra padding and keeps your body from being directly on the foam so it is not as hot.
So I like having the cover.
Thanks for including your estimate of the amount of padding included. That corresponds with what the Amazon picture shows, and also what I would think would add “a slight bit of extra padding” or “a little bit of cushioning.” I was, therefore, staggered to search through the customer reviews on Amazon, and found that several purchasers who were happy with it described it as “soft and thick.” Has “1/4 to 1/2 in thick” been typical of your experience with these covers?
The amount of padding is of concern to me because I need to add more cushioning than that. When I started looking at mattress covers, I had the impression that the ones that look “puffy” on their Amazon page were that way because the individual cells or compartments were stuffed with more fiberfill. I also thought that more fiberfill would provide more insulation, and reduce the heat retention of the memory foam even more. Have you ever used one that’s a lot thicker than the Zen Bamboo, and found that to be the case?
I have had past mattress protectors/ mattress covers with more fluff and thickness than this Zen bamboo one. However those were some time ago and I dont remember the details. These covers do wear out over time, start to get torn etc, especially after several washings so I tend to replace them every few years But I do know I had some in the past with more padding. Some bedding stores keep these sorts of mattress covers so maybe take a look in stores, eg department stores, Bed Bath and Beyond etc
I’m sorry I’ve been so slow to get back to you. I didn’t see the email announcing that you had replied.
Your mention of the tendency of “washings” to accelerate the pace at which the covers “wear out” leads me to wonder how you’re using them. Are you sleeping directly on the cover, or do you use a top sheet over it? Doing that would probably reduce the frequency with which the covers would need to be washed, but would also probably reduce the air flow through the cover.
According to the marketing materials, that could be a problem, because they claim that increased air flow around the body is what enables them to function. However, you’ve said that the cover helps keep you cooler because it “keeps your body from being directly on the foam.” If you’ve tried both directly sleeping on the covers, and when they are covered by a top sheet, have you found that the addition of the sheet had the effect of reducing the cooling effect, or made no difference?
