I'm quite a fat fellow, but for some reason my wrists and ankles have barely any fat on them at all.  So often times I may have sweat pouring off my face while my ankles are freezing.  I work from home, so I wear slippers a lot, and these are the best I've tried.  They cover my ankles and then some, and are comfortable to walk in--I haven't done any five mile hikes in them but I have been up and down the street a few times for quick constitutionals and they work just fine.  I've only had them a couple of months, so I can't say yet how long they'll last, but they didn't cost a mint so I'll be buying another pair when these wear out.  Hopefully Amazon will continue to carry them so I'll have that option.