Diane wrote an answer about KEEN Revel Boot - Women's on May 2, 2012
I have been hiking in mine in all weather types and temps, the only complaint I have is they are not water proof. I stepped in a puddle up to my ankles and they were wet inside when I got to the car, but my feet were not cold. I think it all comes down to the kind of socks you wear. I have light to heavy for the different temps 57-75 degrees it what my hikes have averaged so far. Will try it in the 80's soon.