When these cat beds first arrived I immediately planned to return them because I wasn’t impressed, but I put the opened cat bed on the couch so I could repackage it, and cat number one got on it and stayed.  So I opened the second cat mat, and cat number two did the same. It’s not obvious how it’s self warming, but it is, and both cats love them. I put them on their window cat perch, and they spend most days there.  It’s a good product, fairly priced, easy to use, and cats love them.