This mattress retains heat like no other mattress I have ever owned. My husband and I both wake up frequently tossing and turning trying to find a cool spot on the bed. It is almost tolerable in winter, but I am dreading warmer weather. I would have given it 1 star but my husband does like the support for his back. I can't wait to get a new mattress and we've had this one less than two years. It is already getting dips and lumps too. Also it is very heavy which makes it difficult to tuck the sheets under.