Normally Crocs have some sort of ventilation system in place (meaning holes, slats, etc.)  These do not.  And since they do not, and since they are not meant to be worn with socks, and since they are made of rubber, which doesn't breathe -- get ready for sweaty stink feet.  Now let me be clear, the styling and comfort are all there. I'd even go as far as saying these are the most comfortable pair of Crocs I've owned.  HOWEVER, unless you plan on always washing your feet the second you take off the shoes, be warned...