RE: COLD WEATHER HUNTING?
wow,20 degrees!!! some times i wish it was that warm out.i live in the southern adirondack mts of ny and get a little cool here. i find and read your body will start to adjust to the cold but it takes some time. like a couple of weeks for a few hours a day.the first part of bow season here isn't too bad,by the end of oct i'm so used to the cold that a 60 degree house is warm to me,but not to the better half.
now as far as clothing i dont use cottonit holds too much moisture. go with the man made,,poly type.or wool they keep you warm when wet.a good knit hat( you lose a lot of heat throught the head)
eat a good meal and drink a lot of fluids with out caffine.caffine restricks blood vessels.and not drinking enough will dehydrate you so the blood wont flow as well.
just sitting in the cold makes you matabilisem work more, buns fat and the by product of that is urine.so you have to go even if you dot drink. hope this helps.