When I was younger, I never knew that it was possible to be warm in the winter while I was outside. I just thought that’s how it was. I would wear so many shirts, sweatshirts, and jackets on the top half of my body, but for my legs it was usually just a pair of socks and jeans. I was just constantly cold and I just thought that’s how life would always be in the winter. A near popsicle-state for four or more months of the year.
It unfortunately wasn’t until I was in college that I figured out how crucial proper layering is to staying warm in the winter. Layering up to keep warm has been around for hundreds, if not thousands, of years. Luckily during that time, our technology for clothing has changed drastically too! When done correctly, you will feel as if you could be out in the cold all day long. When done wrong, you’ll probably just want to head back inside as soon as possible and hibernate until the spring thaw.
Your Base Layer
This is the layer that will be worn right next to your skin. This layer’s main purpose is to keep you dry by wicking the moisture away from your skin. Staying dry means staying warm; otherwise you run the risk of having those cold and wet chills. In the worst of situations you can even become hypothermic!
Base layers come in a wide variety of weights and materials:
Weights
You’ve typically got a choice of light, mid, and heavyweight. Without getting into too much detail, it’s just easiest to say that the heavier the weight, the warmer the layer will be. But just remember, this layer’s primary purpose isn’t warmth.
So while it may be tempting to get heavyweight base layers for everything, if it keeps you too warm and you start to sweat faster than the moisture can be wicked away from your skin, you run the risk of actually being colder than you would have with a lighter-weight layer.
Materials
There are lots of different types of materials to choose from when it comes to base layers. The most common ones are synthetic fibers, natural fibers such as Merino wool or even bamboo, and silk. Each of them have their own pros and cons in terms of wicking power, warmth, odor blocking ability, and durability. But most people usually buy what material they are used to.
I personally prefer Merino wool and try to use it as much as possible. It’s not itchy because it’s a smaller fiber, it’s naturally antimicrobial, it fights odors really well, and it’s just so freakin’ soft and comfortable!
Your Mid-Layer/Insulation Layer
This is the layer that will determine how warm you are. That’s because this layer adds little pockets of air all around your body. These pockets then warm up and trap that heat next to your body and keep you warm! It’s really that simple. Typically, the bigger the air pockets, the more heat that is trapped next to your body; and this means you’ll be warmer!
You can choose from a variety of types of layers depending on your situation. You can even double or triple-up if you need to!
Fleece Layer
Fleece is an absolutely killer mid-layer. I have a handful myself. It’s crazy lightweight, so it won’t feel like it’s weighing you down while wearing it or in your pack. It also doesn’t cost very much, so you can stock up on different styles and weights that will cover many different situations. Anywhere from super-lightweight to heavyweight will have you prepared from cool summer mornings to cold snowshoe hikes in the mountains!
Lastly, it also continues to help keep you warm when it gets wet. You’ll still feel uncomfortable because you’re wet, but at least you won’t go hypothermic! That’s because the fibers don’t compress nearly as much as down does when wet, which means there’s more room for those air pockets to form. Those are the air pockets that we talked about earlier that keep you warm and cozy!
Down/Synthetic Insulating Layer
If you want to stay warm, grabbing your puffy mid-layer will do the trick! These jackets are excellent at forming giant air pockets. And remember, those air pockets are what will be keeping you warm. If the weather starts to warm up, these can be a great outer shell provided there’s not much wind. Both down and synthetic filled jackets these days are very lightweight too.
Down vs. Synthetic Fill – I feel there is always a need to mention the difference between down and synthetic insulation. It’s really up to you, your preferences, and the type of weather that may be encountered. Here it is in a nutshell, without going down a fluffy and warm rabbit-hole:
- Down has a great warmth-to-weight ratio. Meaning down will generally keep you warmer with an overall lighter weight jacket than a comparable synthetic filled jacket.
- However, if you encounter wet conditions, then a layer with synthetic fill will be your best friend. It keeps you much warmer than down when wet. Down loses its loftiness and compresses when wet, but not a synthetic fiber! This means synthetics will keep those warm air pockets more intact than down. Synthetics will also dry much faster.
- Lastly, down fill layers will generally pack down much smaller than a comparable synthetic fill layer.
Your Outer Layer
This is your shell layer, meaning, this is the layer that has contact with the elements. There are many factors to consider here too when choosing the right outer layer for you. Do you need breathability? Do you need it to be waterproof? Maybe just a wind-resistant shell? What’s a soft shell jacket?
Wind and water will suck that heat away from your body and make you miserable in no time flat if it’s not managed. The wind will suck out all of that precious body heat you’ve built up under those layers. The rain can compress those down/synthetic fibers which reduces your warming ability. If it creeps into your other layers it can even affect breathability and trap moisture inside your layering system, which will have you chilled in no time. Almost all outer shells these days are treated with a Durable Water Repellent (DWR) finish which helps the water just roll off your jacket.
Types of Shells
Water-resistant and Breathable – These jackets can repel light rain, keep most breezes from making you chilly, and breathe very well. If you plan to be very active and there’s really no threat of a storm (only light rains to drizzles), then this would be perfect.
Soft Shells – Soft shells are basically a slightly more insulated version of the water-resistant and breathable shell we talked about above. They typically have a small fleece layer built-in on the inside. They function the same.
Waterproof and Non-breathable – These will keep you dry and keep the wind out, but if you plan to exert yourself in any way you’ll likely end up sweating through all of your precious layers. Remember those $5 ponchos your parents would put you in? Ever buy a rain jacket at Wal-Mart for $18? While they have their place for activities where you don’t have to move much, in most cases you’re best suited to pick something else.
Waterproof and Breathable – This layer can handle pretty much anything thrown at it, though it comes with a cost; literally, it can be quite expensive. It will keep you dry, keep the wind out, and allow your perspiration to escape in moderate activities.
Materials
As mentioned earlier, base layers come in a variety of different materials. As long as it’s labelled as a base layer, you can bet it will wick moisture away pretty well. I’ll talk about the main two materials: Merino Wool and Synthetics.
Merino Wool – This is my personal go-to choice. It’s super-soft thanks to its incredibly small fibers, it wicks moisture away very well, and it’s naturally antimicrobial which dampens odors. It can be woven together with other materials to increase usability and durability too!
Synthetic – Typically made from polyester, nylon, or a blend of both. They are usually the best at wicking away moisture; which is why most athletic wear is made of it! However, it can develop an odor faster than other materials. So make sure you have some spares if you’re out for a few days!
Cotton Kills – Lastly, I always mention that Cotton Kills. Not all of the time obviously; it’s not like it’s waiting behind trees to get you or anything like that! But cotton is dangerous in the outdoors and when your exertion level is medium to high. Cotton holds onto moisture very well and doesn’t wick it away; that’s why towels are made of cotton! Avoid cotton base layers, jeans, and cotton shirts when performing any kind of activity that may cause you to warm up and/or sweat.
If you sweat in the winter with cotton and then you cool down, the moisture in the fibers will keep you cold and you could develop hypothermia in no time flat. Same in the summer! That breeze may feel great at first after a hot and sweaty summer’s day hike on the trail. But after some time, you’ll get chilled and can still develop hypothermia while it’s 95 degrees out!
Thanks for sticking with me through to the end of this! I hope this helps your understanding of layering and why these items are essential if you want to stay warm in the cold! Remember, you can wear as many layers as you need to in order to stay warm/dry; whether it’s one layer or nine! I had a coworker who used to wear 6-9 layers whenever we taught classes in the snow. As he got hot, he’d shed a layer. And if he got chilled, he’d put more back on!
See you out there!
– Thomas
Field Notes by Gear Up 