This is a sturdy bed that my dog loves to sleep on all night long. I've machine washed and dried the cover, and now have a sheet over the cover as stuffing the block of foam back into the cover isn't something I want to do too often. We have slept on a Tempurpedic mattress for years, the same type of memory foam as this dog bed. Putting plastic or even a pad between the foam and the person or dog adversely affects the benefits of the memory foam. I was unsure of the size to buy and went with the XL. My Lab is large at 75 pounds, but not huge, and the bed is bigger than he needs. The 38 inch width is the same as a single bed, and the length is 4 feet. The Large size would have taken up less space in our bedroom and also been less expensive.