Whether you’re out and about in the city or putting in long days in the mountains, dressing in layers is a no-brainer for cold winter days. The key to building a system that works is understanding your layers’ functions and how the work with one another. Once you put together a kit that works well for you, you can mix and match its components to adapt to any weather or situation.
Baselayer: This is the next-to-skin layer that wicks moisture and regulates your body temperature. Usually this layer is made of merino wool, capilene or bamboo and fits fairly snugly.
Insulating Layer(s): Also called the midlayer, your insulation is typically a fleece or puffy jacket that goes over your baselayer, and works by trapping warm air close to your body. In some situations, you might need a fleece and a down or synthetic puffy jacket. Since puffy jackets tend to be very packable, it’s a good idea to always have one in case you stop moving or there’s a sudden drop in temperature.
Shell: Your outermost layer, or shell, should be a totally waterproof rain jacket that can be added in case of precipitation, or used as a windbreaker at higher elevations. You’ll want to ensure that you choose a jacket with high breathability, since too much sweat will wet out the inside of the jacket and defeat its purpose.