This is the mattress topper that prevents overheating and chills using a fabric originally developed for NASA to help astronauts adapt to extreme temperature shifts. Exclusively available from Hammacher Schlemmer, the topper contains millions of invisible microcapsules that absorb excess heat from your skin when you are hot and release that stored warmth when you are cold, creating the optimal sleeping environment. The topper requires no electricity or wires, and it adjusts independently to each individual's climate, so two sleepers will remain comfortable all night. The topper is filled with 16 to 19 oz. of plush polyester fiberfill, depending on its size, and stitched with a baffled box construction that adds loft and durability. The top layer is stitched from soft 300-thread-count cotton sateen. Spot or dry clean.