Hi. I am new here, and am looking for suggestions on an extra firm mattress topper that is chemical free and sleeps cool (Queen size bed) . We currently have a pillow top mattress that has saggy dips all over it, I have tried a memory foam topper in the past, and it was very hot.
A topper can be a good solution for a mattress that is too firm and that just needs some additional softness and pressure relief as long as it doesn’t have any soft spots or sagging in the sleeping surface but it’s not a particularly good solution for a mattress that is too soft or has developed soft spots or is sagging because a topper will just “follow” the soft spots or sagging underneath it. At best it may be a partial or temporary solution and at worst it can make any issues that you are having with your mattress worse. For example you could end up with a sleeping system where the top layer (the topper) was too firm for you to provide good pressure relief but the layers underneath your topper are either too soft or are sagging too much to provide suitable support to keep your spine in good alignment.
There is more information about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel”.
The most effective way to “fix” a mattress that is too soft or that has developed soft spots or is sagging is to remove and replace the foam layers that are breaking down and not to add something additional on top of them. There is also more information and suggestions about mattresses that are too soft or that have visible or virtual impressions in post #4 here that may be helpful.
While it’s not possible to quantify the sleeping temperature of a topper or sleeping system for any particular person with any real accuracy because there are so many variables involved (including the type of mattress protector and the sheets and bedding that you use which in many cases can have just as significant an effect on temperature as the type of foam in a mattress) and there is no standardized testing for temperature regulation with different combinations of materials … there is more about the many variables that can affect the sleeping temperature of a mattress or sleeping system in post #2 here that can help you choose the types of materials and components that are most likely to keep you in a comfortable temperature range.
If you tend to sleep hot though I would tend to avoid memory foam which tends to sleep warmer than other types of foam materials.
If you decide to try a topper anyway then post #2 here and the topper guidelines it links to has more information and some suggestions that may be helpful (although they are designed to help choose a topper that can provide some additional softness and pressure relief and not to “firm up” a mattress that is too soft) and includes a link to the better online sources for toppers I’m aware of as well. I would also make sure that any topper you decide on has a good return/refund policy just in case it doesn’t work out as well as you hoped for.
This is a common request I receive at my store - adding a topper to a mattress with bad body impressions with the hope that the topper will fill in those impressions, much like pouring water into a mold and having everything resolve to a new level surface. Unfortunately, as Phoenix related, the foam can only contour to what it is placed upon and it will eventually accentuate, not repair, the body impressions… Your end result will be more comfortable body impressions. It’s akin to a home developing a crack in the wall on the second floor as a result of an uneven foundation and spackling the crack and having it reappear time and time again. To fix the problem you have to address the lower levels first. It’s the same with your mattress issues. Unfortunately, unless you have a segment system, you may have limited options to repair the impressions of the mattress. Hopefully some of the suggestions listed in the links provided by Phoenix work for you.
I just realized that you were also asking about “chemicals” and there is more information in post #2 here and the more detailed posts and information it links to about safe, natural, organic, “chemical free”, and “green” mattresses and mattress materials that can help you sort through some of the marketing information and terminology that you will encounter in the industry and can help you differentiate between them and answer “how natural is natural enough for me” or “how safe is safe enough for me” so you can make more “fact based” choices on the types of materials and components you are most comfortable having in your mattress. These types of issues can be complex and are generally specific to each person and their individual sensitivities, circumstances, criteria, beliefs, and lifestyle choices.