When you sweat when it is -30°C. When you are wet but have to keep running. When you need to stay dry and warm in all conditions, you better see how evolution has solved this task. The secret is air, one of the best thermal insulating materials Mother Nature can provide. Alpacas, like polar bears, have hollow fibers filled with air. The Airpaka TM Base Layer will help keep your body temperature in the most extreme conditions. It is made of the finest alpaca fiber, it doesn’t itch and won’t smell even after weeks of use.