I have a great "Lady Englander mattress and innerspring but

use a 2" Memory foam" topper over it. The toppers are not all the same. Search for toppers made by Carpenter Company. They are great and do not retain heat. Cost a little more than the other ones but worth the few extra dollars. I had a cheaper one years ago but that one did retain the heat. I spoke with a sleep expert who told me about the differences. The one I have is great for me as I have back problems. Read the information about the need of thicker ones. It seems that research shows that the body does not use any more than 2 inches of the foam. Any thicker and you may be wasting money. I could never go without a topper again. I place it on top of the mattress, under the pad. Never had a complaint. And the total is far less money than buying a memory foam mattress. PS, I do have an older regular foam mattress for the guest room and that one does get warm. I put a topper on that and it cured the heat retention problem.