I researched quite a bit before purchasing these.  When the box arrived imagine my disappointment when I realized they had sent the wrong size!  (I ordered a size 7 and they sent a size 8).  However, I am glad they did as they seem to run small.  Maybe it is the lining or the fact that I like to wear socks.  I love these so much I am considering ordering another pair!  They definitely keep my feet warm!