I was a great fan of Crocs because they are so very comfortable.  I bought a cute pair of Malindi slingbacks a couple years ago and inadvertently left them in the car overnight.  The temperature went down to about 40 F.  Oddly, the next day I discovered that one shoe of this pair actually shrank from size 7 to about a 4!  I could not even get my foot into it.  Too bizarre. I haven't bought Crocs since.