How cold? And what are you using them for?

For treestand hunting in extreme cold I use military surplus white Mickey Mouse boots. They're between $30-50 on E-Bay, retail for $160, and work great in -20 F. weather (North Dakota end of December). I haven't bowhunted in colder temps than that. hehe I think they are rated to -40F. You probably don't mean that cold. So back to the questions.