The key to managing your body temperature while hiking is dressing in layers. Depending on your adventure, you might start before sunrise in freezing temps, and go well into the afternoon heat. Moving at a steady clip uphill with a backpack on is a surefire way to work up a sweat, but doing so in winter or at altitude means that when you do stop for a break, you will cool down fast and need to bundle up. It’s not unusual to start out in a few top layers, get down to one, then wind up back in all four plus one at the summit. The great thing about layers is you have all these combinations at the ready and can peel them off and pile them on each time the weather or your personal thermostat changes. So let’s look at what all these layers are.
Upper Body Underwear
Your first upper body layer, the layer closest to your skin, is your sports bra, tank, or camisole. Many options are available for this layer, but you’ll want something with support, something without buckles, something that wicks moisture. Sports bras come in everything from somewhat skimpy to tank-top-like coverage, with or without cups, with various strap thicknesses and designs (racerback, classic bra, halter). The only two recommendations I’ll make are one, don’t get adjustable straps as the little buckles can rub and irritate your skin, especially if they sit under backpack straps; and two, go for wider straps over skinny ones as wide generally feels better, especially on long distance hikes. Most importantly, go with what is comfortable for you. That being said, we have some recommendations:
Our favorite sports bra is the Patagonia Barely.
And our favorite camisole/tank is the Black Diamond Campus Tank.
Lower Body Underwear
Some hikers skip underwear altogether, some prefer shorts that have a built-in liner, and some consider their long underwear to be underwear enough in the winter. Good options for women are boy-shorts, briefs, and thongs made of wool or synthetics. Cotton and lace are a no-go (one for moisture retention the other for chafing). Speaking of chafing, look for tagless.
Such a personal item to give advice on, also I kind of feel like if you can’t figure out your own underwear maybe you shouldn’t be out in the wilderness where more complicated decisions present themselves on a constant basis, but here are some recommendations:
REI Women’s Active Brief and the Smartwool 150 Bikini Briefs are both industry standards and are often at the top the Best Hiking Undies lists.
Upper Body Base Layer
Smartwool is your best choice for base layer tops, as wool naturally helps regulate body temperature and has a great capacity to absorb moisture. It is odor resistant, highly breathable, and soft on your skin. Wool helps keep you warm when it’s cold and cool when it’s hot. Generally here in Washington from about October to June, I live in my long sleeved Smartwool top (the Merino 150 crew), and add layers from there. Capilene is a great synthetic alternative to wool that is increasing in popularity and is a favorite option for vegans.
I have worn the Smartwool brand Merino Women’s 150 crew neck top for the past four years. I’m on my third one. I wear (and machine wash) mine an average of 4 times a week almost year round. It’s been to the top of all five Washington volcanoes, a few Oregon ones, literally thousands of miles of local peaks and trails, and with me on my longest days and coldest nights. Just a shirt? Not exactly. A necessity? Pretty much.
Lower Body Base Layer
Base layer bottoms are the garments formerly known as long underwear. Wearing these wool, silk, or capilene leggings under your hiking pants is key for winter excursions. Having warm legs means your core stays warmer. You can regulate your body temp by adding or subtracting top layers.
My REI Coop Midweight Base Layer Tights have been great for a few years now. Whisper soft, they sleep comfortably in a sleeping bag, and are unnoticeable under pants. I’ve worn them alone, under shorts, under hiking pants, under ski pants. My only complaint as a tall person is that unless I have long enough socks, my lower leg is exposed, as they hit well above my ankle. But that’s no reflection on the pants, they’re great. I just wish they came in Long. Hint.
Upper Body Midlayers
Midlayer tops are your fleeces or otherwise soft pullovers, maybe a hoodie or quarter zip. My favorite in this category is a slightly oversized Kuhl fleece. It’s a half-zip so I can easily take it off or put it back on over any hat, cap, helmet, etc, and has a short mock turtleneck so my neck stays warm. My second favorite is an Altra hoodie that has a kangaroo pocket and thumb-holed long sleeves. It’s super soft and has reflector strips for night visibility. Keep in mind that it’s your base layer that is your sweat-management layer; your mid is your cozy layer, the one that will do the work of keeping you warm.
Lower Body Midlayers AKA Pants
So many choices here, but basically you want something comfortable and durable. Pockets for me are a necessity. For summer, some prefer a convertible pant (zip the legs off mid-thigh for shorts). For winter, something with a little thickness while still being breathable is ideal. I’m a huge fan of the REI Women’s Activator pant. I wear them practically year-round aside from the blazing hot shorts days when I’m close to sea level. They are weather resistant—not waterproof but not absorbent—and breathable, with many pockets, and durable enough that for all the scrambling and kicking myself with my own spikes have never torn, and I’ve had them for two years.
Outer Layers: Jackets
A jacket that fits comfortably over your base and mid layers is next. What you choose depends on the weather. A thin puffy, a hard shell jacket, or a Gore-Tex raincoat are the three that I alternate between. However, if it’s shoulder season or an unpredictable forecast or I just can’t decide, sometimes I wear one and bring another. Having a fully waterproof rain jacket in your pack is a good idea anyway. They don’t weigh much, and there’s almost nothing worse than being caught off-guard by rain. They also work as a windbreaker that won’t change your temperature too much.
I received the Arc’teryx Atom as a Christmas present this year, and can’t speak highly enough of it. It has gone with me on every hike since. I call it my magic jacket, because somehow in any temperature, it keeps you comfortably warm without overheating you. It weighs next to nothing. It has worked just as well as a puffy on the few occasions I’ve worn it in extreme weather at altitude, but it also comes with me on short lowland hikes too. Its slim, efficient shape makes it good to run in as well. Deep hood. Deep pockets. Arguably the best jacket in this category.
Way Outer Layer: The Parka
A parka is the Denali coat, the Arctic coat, the one you couldn’t wear casually around town without roasting from the inside out. Usually down-filled (though there are some great synthetics out there), this is an investment piece and one you want to make sure you absolutely love, not just like. I bought mine, the women’s Rab Neutrino Pro, when I started climbing the Cascade volcanoes and needed to be able to tolerate temps near zero. Most hikes it stays home, but if I’m at altitude or it’s wintery, I always bring the big puff. It might only come out on breaks and at the summit, but it becomes more of a safety issue than a comfort issue when temps dip into the twenties. Depending on where you adventure, a parka might not be necessary. But if you plan on doing anything involving cold or altitude, invest.
Outer Layers: Goretex Pants
Waterproof rain/snow pants are a real gamechanger, especially if you live in a wet climate. Here in western Washington where it feels like it rains more often than not, if we waited for clear days to hike, we’d never leave the house. Get them oversized enough that you can pull them on over your pants. Like a raincoat for your legs. A full-leg zipper is ideal, as you can pull them on and off not just over shoes, but over mountaineering boots with crampons attached. When it’s weathery enough to warrant putting these pants on, you aren’t going to want to take your boots off, and you’re going to want to be as efficient as possible. Not to mention if you want to do any glissading, this will keep your pants underneath perfectly dry. And make you go faster!
I got the REI Rainier Full zip pant when I registered to climb Mount Rainier with a guide service. In the months before the trip, I gathered each item of gear on their Gear List. The coincidence of the name wasn’t the only reason I went with these. The full zip — ankle to hip — makes such a difference. They are waterproof in downpours. You can sit in the snow and not have a wet bottom after. They help stave off that brainfreeze-inducing bitter cold that can whip around the tall peaks. A must-have for your backpack’s backup gear pocket.
Wool, wool, wool. Nothing but wool socks. Unless you have an allergy and have to do synthetic, go with wool. Wool keeps your feet warm in the winter and cool in the summer, but most importantly it keeps them dry in any temperature by wicking the sweat away from your skin and absorbing it without winding up heavy and wet like cotton. Myth: the thicker the sock, the warmer it is. It may feel that way if you’re just walking around your house in cozy socks, but once all that coziness gets jammed into a boot, it has the opposite effect. You need the space inside the boot in order for your body temp to create warm air pockets. When it’s very cold out, you need a warmer boot, not more socks. During the summer, wool socks help prevent blisters from forming because your feet stay dry.
Personal preference here. I know folks that swear by them and others that can’t stand them. Liner socks, also called sock liners, are an ultra-thin, practically see-through, silk, nylon, polyester, or wool sock worn under your regular sock. If you are blister-prone or plan on hiking incredibly long distances, you might want to give them a try. They work to prevent blisters by reducing friction and wicking moisture away.
These things may seem like accessories or little extras, however, they could easily mean the difference between misery and comfort, failure and success, safety and serious problems. Temperature is at the root of many rescue operations, either weather-wise or person-wise. Mittens could be the one thing that saves you from frostbite, or a balaclava from windburn. Here are some pieces that you’ll want to add to your pack ASAP
A wool beanie works wonders in cold weather to keep body heat in. A billed cap will keep the sun off your face and out of your eyes on those days with miles of direct sunshine. A wide-brimmed sun hat is a must for you desert hikers.
This head/neck/face covering looks more like something you’d use to rob a bank, but if you are hiking in bitter cold, the full coverage will feel great and prevent your nose and ears from freezing.
Buffs are so versatile that I keep one with me at all times: to put my hair back, to protect my neck from cold or sun, or to cover my face. Nowadays, to use as a mask.
Gloves and Mittens
Covered at length in the Gloves and Mittens article, I would almost put these on the Ten Essentials list as something to have in your pack at all times. If anything should ever happen and you have to spend an unexpected night out, you’ll want to protect your hands from the elements because 1. You need them to do all the other things, and 2. Your body pulls heat away from them first to keep your core warm.
Putting It All Together
The biggest thing I’ve learned about layers is that it takes a lot of trial and error. You may have some over- or underdressed days on your journey to being comfortable, and you need to remember it’s not an exact science—each of our bodies operate differently, we all have different temperature comfort zones, and the weather variables that go into determining what we feel vs. what the thermostat says can keep us guessing like crazy. 80 degrees with a light breeze on a dry desert morning is beautiful, but 80 degrees with 70% humidity bushwhacking near ponds is gross. Same with cold—being on a glacier in the dark can be perfectly comfortable until you throw in some 30MPH wind, then it becomes miserable without the right gear.
So play with it. And always err on the side of “just in case.” For the weight of one more shirt or an extra jacket, you’ve insured a pleasant day in the mountains. You might find yourself coming up with some unconventional combinations (my personal favorite here in Washington being the Camp Muir break-time tank-and-puffy combo) but truly it’s whatever works as long as you are safe, dry, and comfortable. One thing we can never control is the weather, but one thing we can always control is what we wear.
Wendy Harrington is a California native who has lived in a small town at the foothills of the Cascade Mountains in Washington state since 2001. Her love of trail running and peakbagging has led her to summit all five Washington volcanoes, climb to the high points of three states, and put nearly a thousand miles a year on her boots. Her loves include ridgelines, saddles, granite, one-day pushes on big mountains, anything volcanic, long solo days, and objectives that push limits and test endurance.