I'm going to figure that the problems you had keeping your feet warm were when you were on stand & sitting still(??). If that's the case I'd recommend you look around at some products known as "boot blankets" or something similar. They are insulated booties that you pull on over top of your boots and they work very well at keeping your feet warm when you're not moving about. Here's an example of what I'm talking about
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http://www.deergear.com/product/Mens...ategoryId=2856