Not being a backless shoe person, I was skeptical that I would like a "semi-mule" style slipper, but I have be pleasantly surprised that they stay on my feet so well. The slight lip at the back seems to do the job. They are significantly warmer than the slippers I replaced, which is to say very, very warm. No cold toes when I have these on. My only slight dissatisfaction, and it is very slight, is that these slippers seem excessively wide. I have D-E width feet and these flop around rather a lot when I'm walking unless I wear two pairs of heavy-ish socks.