For slip-on's these are very comfortable and not too hot.  I live down in the panhandle of Florida, very hot and humid.  First day I got these, I broke them in by going to a big music/art festival in Dothan, Alabama.  Walked a few miles and stood around for hours, my feet were fine.  If there was any discomfort, it was from standing too still or just being a fat boy walking around too long.  I will buy another pair of these in brown for sure.