In the winter months, when the tempurature drops well below freezing, it gets harder to stay warm enough to be comfortable.  Yes, wool socks are better than cotton but; battery powered heated socks are even better. And yet our feet end up cold at some point anyways.  When we are hunting we are usally trying to be as still as possible, for as long as possible.  The problem is, when we aren't moving, our blood circulation slows down.  We especially lose circulation in our legs and feet if we are sitting or kneeling for long periods.  Our blood is what keeps us warm, and if we are not getting enough of it to our feet, we end up with numb toes, or worse, frost bite.  

One way to combat this is toe exercises.  Wiggling your toes can be done discreetly inside your boots and not a creature will know.  There are different things that you can try like all ten toes up-down, up-down, up-down.  Or alternating left foot toes up, right foot toes down.  Curling your toes, then clenching and releasing, doing this at different speeds, synchronized or alternating, can really get the blood pumping. That will help you keep those toes a bit warmer.  Also, if you count your reps silently it can help pass the time go by until that trophy animal appears.