I purchased these slipper/booties for my wife who just raves about them.  First, they fit perfectly!  Snug but not tight.  Warm but not hot, they have excellent construction and the inside bottom/exterior sole provide excellent cushion and disallow cold from seeping in through the bottom.  There are few things worse than cold feet... there are few slippers better than these (if there are, I haven't found or heard of them).