I wasn't cold just not sweating or maybe getting enough heat in the muscles to loosen up I had on a tshirt and a thin fleece shirt the last couple days
I took a cloth carpenters nail pouch and put a couple big hand warmers in it and put it on backwards under my flannel shirt. It then puts a warmer over each kidney on your back. The blood in your system goes through the kidney twice, so it warms it up good, and sends it throughout the rest of your body, keeping you nice and warm.