I bought this for my son's 4 "memory foam topper. He was complaining that his topper was making his bed too warm. I've heard that complaint and read about it too. So I purchased this cover in the hopes it would make it not so warm. He loves sleeping on the topper so much that he doesn't want to get out of bed. The cover was so comfy looking all by itself. I'm sure it just added to the comfort of his bed.