In the summer of 2014 I was faced with one of the hardest challenges I'd seen yet in my time of backpacking. It was September and I was traveling through the high elevations of the northeast, 1800 miles into the Appalachian Trail, hiking north and having no intention of stopping before reaching the final 2180’th mile in Maine. My body had burned its stores of fat, I was lean, constantly hungry, and as lower Fall temperatures arrived I was suddenly uncomfortably cold. Pretty soon I was wearing every item of clothing I had straight through the day and night (I’ll point out why that is a bad idea later). After a week of doing so I realized that I could not continue my current strategy and I had to make an extra stop in a town to re plan my gear. Here is some of what I learned through this experience:
A good way to think about your apparel is to break it up into three different layers. This way, single layers can be added, removed, or swapped for heavier or lighter pieces when you're too hot or cold.
In this post I want to discuss the basics of the layering system, how to pick the right pieces and materials for your layers, and share some tips to keep in mind in regards to what you wear.
Baselayer (1st Layer) - I always recommend a baselayer top but when it gets colder be sure to add a layer to your legs as well. A baselayer should be close to your skin, not compressing, and made out of a wicking material (I’ll talk more about materials in a bit). The baselayer is meant to absorb your sweat to keep it off of your body. At a minimum, a baselayer is a t shirt but in the cold I often wear a long sleeved pullover on its own or on top of my t shirt. The same rules apply for your socks, be careful to pick wicking socks and make sure they aren’t too tight in your shoes.
Your underwear is your first baselayer! Be sure to have the right material for your unmentionables to wick sweat and avoid chafing.
The mid layers: Think of this layer as the puffy piece of your wardrobe, a good midlayer will add air between your layers which will then warm up and keep you warmer. Some good options are a fleece or a synthetic or down puffy jacket. If you don’t have either of these options a synthetic sweatshirt will work but probably won’t be as puffy and therefore not as warm.
Shell - Your shell is the windstopper and moisture barrier between you and the outside. Look for something waterproof with a hood for your top, a good pair of rain pants or snow pants will work for your legs. Some other cool things to look for: zippers on the underarm to add some air flow if you get too hot, sealed zippers for extra element proofing, or built in reflective linings to add some more heat. Some shells even come with a detachable midlayer. If it is over 35 or 40 degrees I find that using my year round rain jacket over my other layers is enough to block the cold.
Be sure sure that it’s not too tight! A good fitting Shell should have room for layers underneath and won’t compress your midlayer. Lofty midlayers create more warm air than compressed or tight ones.
All three layers can come in all kinds of weights and warmth levels. I like having a light midlayer with me for spring and fall activities and a thicker heavier one for winter. Down or synthetic jackets can also come in an array of insulation values, if you are too cold with your current layers it might be time to find a heavier midlayer.
Start your activity slightly chilly.
This will take some trial and error. I like to think that I should be refreshingly chilly when I walk out my door, not shivering. This will help ensure that you don’t sweat too much when your body warms up. Depending on the temp I'll add one or two layers to my legs and/or top. The rest of my layers will go in my backpack or bike bags in case I need to add a layer or stop.
Keep the intensity of your activity in mind as well, if you are running your body will get hotter on its own than if you are going for a light walk. If your bike ride to work is ten minutes long, don’t stress too much about the perfect silk baselayer or the best starting temperature.
Moisture is cold.
If you sweat heavily while outside you have the potential to become even colder when you stop or slow down. If it's raining or a wet snow is falling, be sure to have your shell on.
Unless it is very windy or wet, I tend to keep my shells in my bag. A shell is good at keeping moisture out, meaning it will trap moisture in as well. If you feel warm enough and it's not raining, take off your shell to let more of your sweat dry. You'll thank me when you stop and have dry layers and a nice shell to cover up with.
Medical Tip: Hypothermia can set in with outside temps of as high as 50 degrees Fahrenheit if your body is wet (According to WebMd). If you are really sweating, a small wicking pack towel is a great way to get rid of some moisture on your body when you do stop moving.
Layer up when you stop moving and take off a layer as you warm up.
On the Appalachian Trail, I stopped wearing all of my layers to bed because I found that I couldn't get warm in the mornings after leaving my sleeping bag. This same thought applies to your active temperature. If you have every bit of your clothing on while you are active, you will probably be cold when you stop. If you're curious, to sleep comfortably I got a sleeping bag liner and upgraded to heavier baselayers. Having layers to add in the morning is crucial if you need motivation to leave a sleeping bag.
In the winter I keep at least one heavier midlayer with me but not on. If I stop or slow down, I throw it on.
Keep your blood flowing!
The human body can do some wonderful things on its own to help keep you warm, one of the best involves keeping warm blood flowing through the ends of your body. If your gloves, shoes, or baselayers are too tight they may restrict blood flow.
Try some extra light warmup exercises like squats before your activity (ideally done indoors before you get cold). Pro tip from Ryan at Switchback: try taking cayenne supplements if you have trouble keeping your extremities warm. This helps aid blood flow!
Picking The Right Material
In hot or cold weather: avoid cotton and cotton blends because they will become wetter and dry slower than most other materials. Think of how a cotton ball sucks up water!
Nylon makes a great shell material because it is naturally a little wind and water resistant. A good shell will still be treated with waterproofing so look for waterproof labels. If it gets really cold, Goretex is a great waterproof material.
Polyester and polyester blends are some of my favorites for any temp. They are wicking, quick drying, light, and often less expensive than wool or silk. Good polyester will provide insulation when wet but not as well as wool. Downside to synthetics: they hold onto stains and smells. It’s not that bad (you know you'll smell no matter what) but don’t say I didn’t warn you if you're out for days on end.
For cold temperatures: Wool and wool blends are some of the warmest materials. They handle moisture really well and if you can’t keep them dry they will provide insulation when wet. Merino blends of wool also keep smells at bay better than synthetics, and man, they just feel nice. Downside: they aren't cheap and they are often bulkier and heavier than synthetic. As a baselayer, cheaper wool items can be scratchy.
For warmer to moderate temperatures: Silk, although more expensive and trickier to maintain, makes a really comfortable underwear or baselayer material.
In 2014 I completed the Appalachian Trail. It took some trial and a lot of learning from my mistakes. I mean at one point I was eating candy bars and doing push ups in my sleeping bag every few hours through the night to stop my shivering, but eventually I made the right moves. Along with the clothing tips I’ve mentioned, I learned a lot about my body in terms of its limits. I look back on that cold section of the trail with a lot of fondness because the cold added a layer (sorry, I like puns) of difficulty. This difficulty can make a lot of people stay indoors, but those willing to be a little cold and work a little harder have valuable experiences and cool stories. And that, is what it's all about.
As always, stop in the shop if you’d like to talk layers. Or feel free to email questions to me directly at firstname.lastname@example.org
WebMD source on hypothermia: http://www.webmd.com/first-aid/tc/hypothermia-and-cold-temperature-exposure-topic-overview