ORIGINAL: Red Lion
Someone else here gave me the tip before, so not really mine, but....Using the thermocare back heat pad. I used them/one each time out while hunting during ML season and the extra warth for my core/back made me feel much more comfortable when cold out.
I read that too and forgot already. I'm adding a few of those to my list to try this year. In Southern Illinois you can have bone chilling temps during deer season, or I've set around second season in lawn chairs outside in the evening in tee shirts.