Thanks, Sabby, for those links! I may have to try the one for runners with the cooler (supposedly) moisture wicking properties. I did flip the mattress last night (ugg...heavy), and then put the cotton futon mattress on top of it, and it did feel better. This mattress, which I bought because it was firm and on sale, has some kind of unique fibers running thru the top part, which may be metal or plastic, retaining heat, for sure. The back side is plain, and I expected it to sink in with me during the night after flipping it, but it didn't and it was, indeed, somewhat cooler, though not enough so! The cotton filled futon mattress which I've placed on top of the mattess is great, and very firm, but I think the cover is treated with with some sort of moisture and stain resistance, and a 100% cotton mattress pad is needed.
Got to get a good night's sleep.
Love
Patty