Purchased these for our 8 year old.  We originally ordered size 8; but, they were a little short.  Sent the 8 back for a 10-12; they are a little bit long, but we kept them.  My son wore these this past weekend at Hawksnest tubing resort in NC where the temperature was down in the low thirties.  My son loved them & was never cold; sometimes, overly warm when doing activities.  I personally purchased an adult pair of pants from L.L. Bean; however, although they are plenty warm, I am returning them because the fabric makes too much noise when I move.  I will attempt instead to find an adult pair of Columbia similar to these since they do not make noise.