I can't understand all these reports of sweating. We have a newish bed with a memory foam mattress, and the same foam is on toppers on all the other beds. Not one person's complained about them being too hot! These so-called memory foams vary a lot though. Our bed was expensive, but guaranteed for a minimum of 10 years, so if you decide to go ahead and buy, I'd advise going for the dearer end of the market if possible. They're impossibly comfortable, and i'd never go back to a "normal" mattress again.