Staying warm and dry in winter is all about dressing in layers. One of the most important pieces of gear you can wear during cold weather fly fishing operations is a quality base layer. What was previously known to outdoors men and women as a "Union Suit" or "long handles" has evolved into a technical garment designed to keep your core both warm and dry even when exerting yourself in cold weather.
Anglers can choose to gird their loins with natural materials such as Cotton, Merino Wool, or even Silk. However, advances in textile science have evolved some excellent synthetic materials such as Patagonia's Capilene (pictured above) which is known for its excellent wicking properties during aerobic activity. Patagonia's website has an excellent page discussing the differences between each fabrication that they offer.
