I like keeping this bed on my porch for the dogs. We had a light rain and the cover got a little wet. I took off the cover put it in the dryer on low.  15 minutes later I took it out of the dryer.  The cover was not dry but the inner mesh was melted.  The closed zipper came undone.  Now I have a dilemma. It looks like I'm going to have to sew a cover to fit and use Velcro instead of a zipper. The mattress itself is great for the dogs, the cover, the sewing was done extremely cheaply. The cover while not a microfiber that I know of does not act as a cooling element for the dog.  I'm going to use an older sheet to make a slipcover.  That way I know my dog will be cool.  Three stars because the foam itself is of good quality.