Adventure is all about embracing the weather conditions, whatever it throws at us, and using the layering system effectively is essential to staying warm, dry and comfortable in all conditions. A basic layering system has three important functions: to wick sweat away from the skin; to trap body heat; and to protect you from the weather. The most effective way to protect yourself from the cold is to wear multiple layers which can be added or removed depending on the conditions. You will find most hikers, climbers, snow sport lovers and many other outdoor enthusiasts will use an effective layering system.
The base layer is the first layer that sits directly against your skin. A base layer has two main functions- to regulate your body temperature and wick away moisture from the skin. Moisture conducts heat 25 times faster than air, so if it can't escape the surface of your skin, you become cold very quickly. Base layers are made from synthetic polyester or fine Merino wool as they are both very good at wicking moisture. Cotton t-shirts should not be used as a base layer for active use as cotton soaks up moisture and holds on to it, meaning you become damp, clammy and ultimately cold.
The function of the mid layer is primarily to provide insulation. The mid layer's role is to insulate and trap body heat, while continuing to allow moisture to make its way to the outer layers. Usually, your mid-layer is either a fleece or an insulated jacket and just like a base layer, a mid-layer should be breathable and able to retain heat. Mid layer items are also often worn alone (over your base-layer) on shorter trips and in mild weather conditions. The pieces you choose should be comfortable, lightweight and more robust than your base layer clothing.
The main purpose of the outer layer is to protect you from the rain and wind. Often the outer layer will be waterproof and breathable which will allow sweat and water vapour to escape the body and also keep you dry if it should rain. Nothing will save you from the unexpected change in weather like a good outer layer jacket. Whether you’re stuck in sudden storms, faced with drastic drops in temperature, or cresting a ridge to find yourself in high winds, your outer layer will come to the rescue. For a layering system to work well, an outer shell must be both waterproof and breathable, stopping rain entering, but allowing sweat vapour to escape. Try Helly Hansen for some of the best premium cold weather gear available.