This post may contain affiliate links.

Winter Hiking in a Thin Baselayer

Winter Hiking in a Thin base layer

The biggest mistake that new winter hikers make is overdressing by wearing heavy or medium-weight baselayers that are hard to remove if you start to sweat. You’ll be much better off wearing a very thin crew or quarter-zip shirt and adding additional thermal or wind-blocking layers on top of it if you start to feel a chill.

For example, you can exert a finer degree of control over your warmth level if you wear a lightweight baselayer top instead of a medium or heavy one and then add a second lightweight top over it if you start to feel a chill. There’s virtually no weight difference clothing-wise in this approach, but it gives you a much finer level of control over how warm you want to be when hiking in winter.

For the rest of this article, I’m going to focus winter layering with shirts and upper body insulation. For a detailed discussion about how to layer pants for winter hiking, see “Winter Pant Layering for Hikers that Sweat.” The same principles apply here. 

Perspiration is Bad

The problem with being too warm in winter is that it causes you to perspire. Perspiration is bad because it burns more calories, but that’s a hard concept for most people to understand and internalize. A more obvious outcome is that perspiration causes the air pockets in your clothing to clog up with liquid. This reduces the size of the air pockets in your clothing that trap warm air, reducing their ability to insulate you.

Some perspiration is inevitable, even when your body is at rest. Called insensible perspiration, you’re body emits about 400 ml of water per day through your skin. The Greeks were the first people to observe this fact thousands of years ago.

Layering

While you can’t completely stop perspiration, you can manage the degree that it degrades your clothing’s insulation value by wearing hydrophobic clothing that transports any water it absorbs away from your skin. This approach, commonly called layering, is best accomplished by wearing thin, highly porous clothing next to your skin. When layering, you want to preserve that wicking action through as many layers as possible. The goal is to move moisture from your skin to an outer layer where it can evaporate.

For example, I use three core layers in my winter hiking layering system:

  • A thin lightweight long sleeve jersey, usually synthetic.
  • A lightweight fleece hoody
  • A nylon windbreaker

That’s it, down to about 15 degrees. I can tell it’s working because the underarms of my wind shirt are damp and stinky at the end of the day. That means my perspiration is evaporating from the outermost layer.

Winter hikers often strip down to their baselayer when they’re working hard
Winter hikers often strip down to their baselayers when they’re working hard

The Next-to-Skin Layer

I’ve found that the most important garment in my layering stack is the foundational next-to-skin garment. Look for tops that you can see through when you hold them up to the light. I prefer synthetic long-sleeve tops because they don’t absorb as much moisture and are very effective at wicking moisture up to my next layer. Wool can work too, especially wool garments that combine synthetic and wool yarns because they wick like synthetic tops but smell less due to their wool content. They’re also far more durable.

Here are the next-to-skin tops that I use and that you might find useful to try.

But I can’t stress this enough. Keep that next-to-skin layer thin so that moisture can move quickly through it and up into your next layer. While it’s not intuitive, you’ll stay warmer if you stay cooler and perspire less during the day.

Last updated December 2023

See also:

SectionHiker is reader-supported. We only make money if you purchase a product through our affiliate links. Help us continue to test and write unsponsored and independent gear reviews, beginner FAQs, and free hiking guides.

24 comments

  1. Great article Phil currently and am using an IOMerino light weight zip and love the piece. But, I am thinking about purchasing an Outdoor Vitals Dragonwool Hoodie. They are coming back in stock soon. Have a great New Year.

  2. I have two midweight, Patagonia half-zip capilene tops, one medium that is snug and the other is a size large which is “roomier”.
    In your opinion, which size/fit would best wick away perspiration?

  3. My all-time favorite is a Mammut PowerWool 1/4-zip baselayer, which has a very fine micro-grid on the skin side, but it’s really hard to find now, as they seem to have stopped making it. I’ve worn it hiking, biking, and on 20-hour intercontinental trips, and the PowerWool comes through looking good without any funk.

    Recently tried an Under Armour ColdGear compression shirt and found it horrible. Never felt warm and seemed to keep the moisture very close to the body, leaving me clammy and cold at the end of the ride.

    • I agree with this article. I use a Smartwool Men’s Merino 150 Base Layer 1/4 Zip for most winter hiking (snowshoeing) in Sangre de Christo mountains of Colorado. I find it wicks fairly well (maybe not as good a synthetic hybrid) and also keeps me warm when hiking up to high elevation. On the return I just add layers.

  4. I relate to this and use a thin base layer. I’ve reached the summit of a steep climb in 10 degrees with just a base layer with ice crystals growing out of my chest, I have a male friend who would be bare chested in the same conditions.

  5. Great article. I have also found that baggier base layers are warmer than tighter fitting ones of the same weight. They also breathe better, which helps sweat to dry and didn’t feel as sticky when you start to warm up. To prevent drafts when starting out or resting, the outer layers should seal at the waist and cuffs and a thin scarf or buff can prevent drafts at the neck. Regardless, the base is more versatile if it’s loose.

  6. Patagonia Merino Air (renamed as Patagonia Capilene Air) knit base layer is also very good for this.

  7. Been using the HH LIFA crews for years, they are truly a four season item for me. They’ll get used from temps 20’s to 60’s. Below 20 I use a thicker grid fleece top (Under Armour 2.0, which seems to be discontinued), and above 60’s it’s a synthetic short sleeve. Best thing about the HH is they are fairly inexpensive and often are on sale for $30.

  8. Would an REI Swiftland long sleeve be comparable to any of your suggestions?

    • yes that should do nicely. It’s very thin, lightweight, and polyester which wicks very well.

    • Cheri, I’ve been wearing the REI Swiftland running shirts in recent months and found them the absolute lightest and best wicking material I’ve found yet. Much better than the UnderArmour or Nike DryFit shirts I have. If you hold the Swiftland fabric to a light, you can see the tiny holes which REI calls “microventilation.” The fabric is delicate, however, so I’m careful when washing it.

  9. I wear a Nike pro t-shirt and a Houdini wind shirt around 35 degrees and up. Anything lower than that I wear a spyder long sleeve thin synthetic tj- max special ,and the Houdini. I start off cold and within a mile or so I am good to go. I really love the Houdini, it holds in the heat. I unzip if I get too hot and take the hood off. I was late to the game for the wind shirt. It also dries quickly. In the cold I don’t take it off until camp and then throw on packed clothes.,and let wind shirt dry for next day. Thin layers are key for me when hiking in the cold.

  10. I sweat a lot, no matter what. I would have to hike extremely slow in the winter to not sweat…that’s no fun! If I wear a synthetic jersey like a capilene as a base layer in the winter, it just gets soaked no matter what I’m wearing on top of it, and that wet layer next to my skin is extremely chilling and uncomfortable. I’ve dialed in a perfect system that works for me for heavy sweating: Brynje Superthermo T-shirt (the synthetic one), Polartec Alpha 60 hoodie, Black Diamond Alpine Start Jacket. The Brynje keeps me dry, the Alpha provides some warmth, but is also so breathable and also absorbs almost no moisture similar to the Brinye, and the Alpine star blocks the wind and traps my body heat. All the sweat winds up in the Alpine Start. It’s wet to the touch by the end of my hike, but that’s OK, because it’s so far from my skin. The wind does not chill me anymore than if it were dry. If I do get cold, generally when at rest, I just throw on my puffy. This system works for me down to about 15-20 degrees, and I never have to adjust my layers to stay comfortable. If it’s colder, I’ll swap the Alpha 60 for an Alpha 90. As long as I’m moving, I’m warm.

  11. Great article. It took me a while to truly appreciate a good baselayer. I must have 35+ now in a wide variety of weights, styles and materials. It’s definitely a sickness.

    Despite being skinny I heat up quickly and sweat a lot. These are my current go to pieces-

    Warm weather- Arcteryx Cormac line (hoody and short sleeve)

    Cool weather- Ortovox 185 Rock n Wool (both short and long sleeve) and the Patagonia Capilene Air.

    The synthetic ones stick after just one day. The Ortovox can go 3 or 4 before getting stinky.

    YMMV

  12. I have avoided synthetics since they tend to stink, while wool doesn’t. Are there any decent synthetics for those of us whose body chemistry doesn’t work well with synthetics?

    • Farpointe Alpha hoodie. Insanely warm, but breathable. I’ve been dabbling with bamboo t-shirts that are much more breathable than nylon or polyester and really like them. I should qualify that I don’t really care for nylon or polyester against my skin. My cold weather base layer is a merino set from Minus 33. Carhartt makes a wool blend quarter zip that I really like. For me, I’ve found that my temp regulates more comfortably with a natural fiber of either wool, alpaca, or bamboo. Everyone’s different though. Thankfully we have many choices out there

    • Have you had a look at Brynge synthetic ‘string vest’ baselayers? I wear one every day when I’m hiking. My normal warm months of the year covering are my Columbia synthetic hiking shirts, they go well together.

  13. I totally agree, this week I have been wearing a first layer very fleecy and when cooling down no problem to add another layer but whenever the going was getting harder I could feel the humidity and wishing I had taken a thinner layer. Cheers.

  14. If I wear Merino baselayers they make me itch across my torso (I only found out after purchase) so I wear a two-layer system to stop it. I wear a Brynge ‘string vest’ synthetic baselayer and my Merino baselayer on top. It works, no itching and I’m warm. I was introduced to Brynge by my Norwegian daughter-in-law. If I hadn’t bought my Brynge my Merino baselayers would still be sitting in a drawer doing nothing.

Leave a Reply

Your email address will not be published. Required fields are marked *