Microfiber sheets do not keep me cool whatsoever. Soft, indeed, but not worth putting on my bed; bad choice on my part not realizing they were microfiber. Don't get me wrong, microfiber has it's place, but keeping you cool isn't one of them. So shame on me, fool me once. Of course it makes obvious sense, that you can only return an unopened product, but just running my fingers along the sheets isn't enough to gage the coolness that I'd expect to feel across the rest of my body. I'm learning new things, and how to keep cool is one of them. Sincerely, Kevin C.