The mattress come in two parts: a 4-inch memory foam pad and a fitted sheet with a 1.5" (looks more like a 1 inch) polyester padding which spot clean only. For that reason, I placed my regular waterproof mattress protector on top plus a fitted cotton sheet over. We placed the topper over the orthopedic memory foam mattress that we purchased 3 months ago. Both my husband and I felt great improvement in our morning backache. He is 22LB and I am 115Lb, and so far we did not notice overheating. My bed is very comfortable and I wish I had purchased this topper earlier.