I bought these to use on bicycle rides. So far, I haven't used mine but my wife has used hers. She said that it works very well...of course, we're talking about temps of 45F-55F. No way would we be riding if it was less than 45F!!!

Update 01/02/13: I did use mine last weekend and at 48F it worked very well to keep my ears and neck warm and protected from the breeze generated by a 20mph ride.