I have been in treatment for breast cancer and a side effect of the chemotherapy has been terrible hot flashes. We had a memory foam matress topper that I had purchased from Overstock a couple of years ago that I loved, but it was so very hot.This matress pad really does make the bed significantly cooler. When I first get into bed it actually feels cold at times. But I'm greatful throughout the night at the difference. My poor husband on the other hand...... Memory foam holds heat and even with the Iso Cool pad it might still feel warm to someone who has a standard matress. But I can certainly tell the difference between just the memory foam topper and the topper with the pad.The memory foam isn't as dense as our previous topper but still very comfortable. The description gives the density but I really have no idea what our original was so it wouldn't have helped. There was an odor but that's just the nature of memory foam. We aired it out a couple of days....as much as you can find space to do so with a giant king topper. I would say it took a couple of weeks for the odor to be completely gone but it wasn't anything that was bothersome to sleep on those 2 weeks.The original topper we got a few years ago was not exactly the size of our bed but this one was perfect.I would definatly recomend. You can't buy just the pad for the price!