I am a owner of 2 king size tempurpedic mattress since 2004 and love them. I have found these types of mattresses are very room heat sensitive and there as stiff as a board at 50 degrees. We like to sleep in a cool room, Not 50, and it makes the bed firm. It's also easier to move or roll around without waking up in a hole, like when there hot and you do not get night sweats. I suggest finding the right room tempature for yourself and your bed.
I also have a bad back for the last 24 years, and frequently visit a chiropractor for maintance.

Oh my God! This is the worse mattress ever. I felt fine at first later my husband and I both started to hurt in our lower backs and neck areas. It is so bad that I've had to go to the doctor on several occassions. We hate it. We're looking into getting a new mattress. I stay in so much pain some days I can barely walk. The secret; if you have any small amount of behind do not buy this crap. Your body parts sink and that is not kosher. The bed conforms to you figure, it terribly unhealthy. We have only had the bed less than 5 years. By the way the company could care less. We tried to take it back and all we got was mam we can't take it back after 90 days.

I have owned a king Tempur-pedic with their foundations and mattress sack for almost four years. I am satisfied with the sleeping comfort and can not detect any deterioration in the comfort level. No matter how cool we keep the bedroom air temperature, the area of your body that is touching the mattress retains body heat. Has anyone figured out a solution to this problem?