When I hunted in KS this year, it was 19 degrees, not really all that could by comparison but pretty chilly with the wind. I spent five days in Saskatchewan hunting dawn to dusk from a blind that we really just a pile of logs stitched together, got my deer at 1PM on last day, sat there until dark until the outfitter picked me up. Sitting is always much colder than moving about, my feet turn to blocks of ice no matter what I do, lack of circulation is the culprit when sitting for hours. I stand from time to time when I can to help circulation and these days, I never hunt without toe warmers, they are a life saver and the stick to your insoles and you forget they are there except for the warmth. An insulated hooded jacket is a must have, keeps you warm and really blocks the wind if you can turn your back to it. Also, make sure your layers allow for some air in between, don't go to tight. It never got above 8 degrees during that Sask hunt but one life saver was a fleece scarf I bought at the airport, I wrapped it around my neck and zipper my jacket up to it, really sealed off everything keeping my body heat inside.
