I bought these for winter running.  I have worn them down to 20 degrees and my hands were plenty warm.  There is enough air circulation that my hands never got hot and sweaty.  These are not wind proof.  They are meant to be a glove liner, but I just wear them as my winter running glove and they work great.  I also sent a few pair to my son who is serving our country in Afghanistan--winter there too!  He uses them as a glove liner.