Staying warm in the great outdoors can be as simple or as complex as your intended adventure. For the sake of this article, let’s keep things simple and start off with basic building blocks. Look out for later articles where do we’ll venture deeper into techniques and strategic clothing/sleep systems.
In a word we’re looking at layers of clothing. Each layer does a slightly different job, as do the materials these layers are made of. So here’s a basic rundown of what does what?
Skin Contact & Comfort
This is the layer of clothing that touches your skin. Think Long John underwear or those really fitted and tight shirts (ideally longsleeve), socks, and underwear. This layer helps absorb, or “wick,” away your sweat and add insulation for warmth. The reason “wicking” away your sweat is important is that when you’re wet, you get colder faster from the moisture evaporating from your skin. In this example we’re doing a day hike in the cool spring time so we want to stay warm.
Baselayers are meant to stay permanently in contact with your skin, it’s not meant to be an on/off thing, if you find you need to take a baselayer off, your baselayer is most likely too thick for the temperature, therefore use a thinner baselayer next time.
Without getting into the technical details, go for Synthetic or Merino Wool fabric. NOT cotton. Why? Cotton absorbs and keeps moisture, therefore making you cooler (which is why it’s great for hot climates). But for cold temperatures, Synthetic or Merino Wool will wick away your sweat and enable the moisture to move away from your body (moving from an area of high concentration, AKA your skin, to an area of low concentration, AKA away from your skin).
Some examples of mid-layers would be a fleece sweater, softshell shirt/jacket, puffy shirt/jacket. The purpose of a mid-layer is to provide additional layers of clothing for warmth and to continue wicking sweat away from your baselayers that have wicked sweat away from your skin (see a pattern here?). Again same fabric principles apply. Synthetic or Merino Wool (you could do regular wool too if it doesn’t make you itchy). The main takeaway for mid-layers is breathability. You want the material to be breathable to allow excess heat/sweat to be released so you won’t be overheating/sweating too much.
Protection from the elements
This is the layer that keeps wind and rain off of you. Rain jackets/pants or wind shells. Current industry standard is to use a waterproof breathable membrane like Gore-Tex, Pertex, eVent, H2No, etc. The more breathable the membrane, the simpler the jacket can be and the less zippers/vents/gizmos are required to keep you comfortable. Pick a jacket that suits your budget and has features you desire (i.e. pockets, hood, cuffs, etc).
This rounds off Clothing 101 – The Basics. By utilizing this system you’ll be able to adjust what you wear according to your physical exertion, outside temperature, and weather patterns to keep yourself as comfortable as possible. As you go outdoors more often, you will gain experience, learn, and refine this system to suit your unique body type and preferences.
Happy Trails! Terry Lui
Terry is an outdoor skills trainer and educator for a national outdoor retail company. When he’s not working you can find him in the mountains exploring and climbing rock or eating a steaming bowl of ramen noodles (preferably all at the same time). He recently completed a 90 day backcountry expedition in the USA Rocky Mountains.