Wear wool shirts and sweaters, as wool keeps you warm even when it’s wet. We recommend “layering,” using cotton and wool clothing. To prevent getting chilled, the minute you start perspiring take off the top layer until you’re down to your skin, if you have to be. As soon as you stop working hard, start putting the layers back on, slowly, to retain the body heat that you’ve built up from working and sweating. If you get chilled before you put your clothes back on, it’s very hard to get warm again. We have found that carrying the little extra weight of wool clothing will pay off. Keep your hat on, you lose a lot of heat through the top of your head.