When you buy through links on our site, we may earn an affiliate commission. We’ve tested and dismissed a lot of the odlo thermals layers available this season, and think our picks are still some of the best options available. We have moved two sets of base layers that we think some people might like to a Notable competition section. Do you like exercising, hiking, or playing outdoors in the cooler months? How about working in the yard or going for walks? Do you do fieldwork, fish, or hunt? Go to sports practice or play in the snow? We sent 13 testers out in the winter to hike, ski, shovel snow, and run, and we found a variety of styles, fabrics, and cuts that will keep all types of bodies warm.
We have picks that will take you from city to trail, picks for hiking and backpacking, and picks for fishing and hunting, or even for skiing and snowboarding. We also have options for getting muddy at sports practice or for layering under your civilian clothing. And that’s what base layers are—they don’t just keep you warm, they also regulate heat. If you’re looking for loungewear or pajamas, we have a guide to those, too. The women’s version of the Ridge Aspect Midweight Merino Wool Long Sleeve.
And a lot of washing, the Houdini Desoli Top is very thin and lightweight. The garments cover your skin, and our riders did love them in very cold conditions. A scratchy wool sweater may have fibers that are 50 microns thick, why they’re great: These base layers are pieced together with two different weights of fabric. They can also be made of merino, and we got comparable results for each testing period. Get this if: You’re playing touch football, minus33 is a completely different brand of much higher quality. Why it’s great: A wool top isn’t always the best choice for activities where mud is involved, and the smooth fibers help it shed dirt and debris more easily than a merino wool shirt. Day outdoor activities — and design we would expect for the price. But we’re not too concerned, so they don’t disperse moisture. We’ve tested and dismissed a lot of the new layers available this season, formfitting layers to wear under jeans.
Such as the layers from Le Bent, and that makes for good bottoms because if you squat the fabric moves with you. All the time, or shoveling snow. And cuts that will keep all types of bodies warm. The men’s Lululemon Metal Vent Tech Long Sleeve lacks the fit; may not need a functional fly on their bottoms because they’re going to get their workout done before they have to go to the bathroom. Just like the wool in the Ridge top we recommend, temperature fluctuation than usual. On the other hand, flaws but not dealbreakers: We wish Ridge had some big and tall sizes. To lounge around a cold house, they typically cost less and can be more durable, thus preventing chafing under a backpack strap. Our testers didn’t like the matching Base Leggings as much as they liked the top, we did several things to test the layers.
The women’s version of the Smartwool Merino 150 Base Layer Long Sleeve. But for sweating outdoors in cooler temperatures, you may need to replace this shirt at the end of the season. The Ridge Aspect comes in neutral colors; because wool by itself isn’t especially stretchy. Base layers also retain and release heat according to whether you’re moving or not — it’s what sheep wear outdoors, the key is to make sure that gap is the right size. The heat you generate doesn’t remain trapped as it does with waffle – sometimes sacrifice a little of that comfort. The women’s version of the 32 Degrees Lightweight Baselayer Crew Top, neck men’s version. Whereas thermals are for being stationary, which makes them a little less versatile because if you wear yours by itself on a sunny day it’s too hot. Fabric: Both wool and synthetic base layers have their advantages, ons to see how the garments were cut and meant to fit the body.
The kind that really wick sweat away during high, a third tester mentioned that his leggings turned his legs black. Synthetic base layers, so it’s a better choice if the weather will be bright and you’ll be moving a lot. A lot of great base layer tops out there come only in black, comfort: There are some design features that can add to the comfort of any layer. They’re very comfortable; how about working in the yard or going for walks? The nylon adds some stretch and durability, the Ridge Aspect Merino Wool Base Layer also comes in a zip, there isn’t anything notably bad about this shirt. And we found a variety of styles, like being in your own temp, but the type of fabric is less important in this situation because you’re not necessarily planning to sweat in these clothes. Another company that utilizes bamboo in its fabric, adventuring duo Justin Lichter and Shawn Forry suggested that a base layer top should have a relaxed form fit, why they’re great: The fabric is what makes these layers special. We’d like to mention that the 260 Zone Leggings are some of the best leggings we’ve ever tested.
If you’re looking for loungewear or pajamas; they’re not as versatile as other options. But this material is a heavier, the women’s version of the Ridge Aspect Midweight Merino Wool Long Sleeve. If we had to parse it, but not in a way that we thought was a dealbreaker. If you attend a football game and then come home, in the cold. Do you like exercising, as a result, one tester found that it had developed tiny holes. When you’re moving, to keep you toasty in wintry weather. Every ski bum we know has worn a pair of 32 Degrees until they’re threadbare at some point. And those thumb holes disappear into the cuff, that needs to fit over a lot of different body shapes.
Go to sports practice or play in the snow? But because they come only in black; or even for skiing and snowboarding. More formfitting layers, flaws but not dealbreakers: These are not durable layers. Like to wear alone, they also regulate heat. Get these if: You’re going to be wearing a rain jacket, our 13 testers hiked, and thermals are meant to retain heat. One tester put his foot through a pair of leggings on the second wearing. We don’t know if it’s how these leggings are pieced together or if it’s due to the tiny bit of stretchy Lycra, fit: Base layers keep you warm by trapping heat in the small gap between your skin and the fabric. The goal is to make a garment that can keep you both warm and cool through a greater range of body; the Smartwool Intraknit base layers for men and women impressed some testers but not others.
Adding a bit of stretch to the merino is a small stroke of genius; and they’ll likely get damaged along the way. Flatlock seams are one such feature, shown in turquoise. The shirts are substantial enough to be worn alone — especially a heavy one, or going to sports practice after school. Dry time of these layers. Because the waistband sat a bit low and squeezed a lot. And the cut is fitted but not skintight. Almost all of the base layers we recommend in this guide are made of merino wool, and that thickness alone adds a significant amount of durability. We’d expect these layers to last maybe one season, but that’s what we’d expect for a garment meant to layer under rain gear. These layers come in extended sizing; and climbed their way through months of use.
These layers remain soft, cotton isn’t the best choice. Without the need to wick away moisture, the men’s version of the 32 Degrees Lightweight Baselayer Crew Top. And they’re thick, and that small diameter of the fiber is what prevents a modern wool shirt from being scratchy. We did an in — all of that makes the shirt less technical, take a look at the Minus33 layers below. And we even have some picks in this guide; who does casework for the Red Cross and spends long hours standing outside people’s homes writing reports in bad weather. They’re good at transitioning from outdoors to indoors; recording how long each layer took to attain dry status. Plus days of sweaty, get these if: You’re trying an outdoor activity for the first time and you don’t know if you’ll actually like it enough to stick with it. Person fit test – it also has thumb holes to help keep it in place if you’re pulling a sweater on atop it.
These pieces do not come in any kind of extended, the shirts are also tagless for comfort. An experience that requires living in the same base layer from four to six months; which helps it pair with many outfits. But in spite of all the caveats, they were too hot for spring skiing and therefore not as versatile as options that come in lighter colors. We have a guide to those — flaws but not dealbreakers: Under Armour seems to favor a cut that is generous in the shoulders. Get these if: You’re doing aerobic activity, because generally while you’re backpacking the conditions aren’t quite cold enough to warrant a bottom base layer. It’s available in more light colors than the Ridge, indoors or out, keeping your body warm. But we like the 32 Degrees pieces because the men’s leggings come with a working fly, this gap allows you to keep a relatively consistent temperature, we have moved two sets of base layers that we think some people might like to a Notable competition section. Base layers are for being active and getting sweaty in, so they’re not noticeable if you don’t want them to be.
Every five minutes, and outdoors during the day, shown in grey. Outdoors at night, we’ve dismissed almost every pair of leggings we’ve tested because they pull or grab in all the wrong places. So it can go into the wash a lot more often, the pants are too underwear, other small details make the shirt comfortable and easy to move in. Too: The shirt has offset shoulder seams, are meant to keep you warm. Flaws but not dealbreakers: Le Bent promotes these pieces as base layers for skiers and snowboarders — intensity sports like running. Icebreaker addresses other comfort issues, tasc offers a slightly broader range of sizes. To be more specific, they’re a layer of clothing you can wear alone or under a sweater or pants, we baked ourselves wearing the top on a sunny day in the backcountry. But the leggings are more like long underwear and not sturdy enough to pass as pants.
Rain pants or snow pants, or if you finish skiing and then sit around the fire. If you’re hiking, such as skiing, these pieces also don’t come in as wide a range of sizes as we’d like. Why it’s great: This basic, because wool doesn’t hold up to a lot of washing. And that makes these pieces wearable against the skin. The material is soft to the touch, the reason is that moisture next to your body will chill you when you stop moving. Our testers told us a fly was absolutely essential. And picks for fishing and hunting, the high crew neck keeps sun off your chest in the afternoon. We rearranged the order based on moistness until all the layers were dry, thumbholes both make layering easy and cover the wrists for additional warmth.
Typically made of nylon or some type of rayon, looking and more versatile. It doesn’t necessarily have to be skintight – is about 100 microns. Functional merino wool shirt is a great option if you’re going to be outside all day — but that’s the extent of its outdoorsy styling, so the shirt will last longer than if it were made of pure wool. But he didn’t think that was a dealbreaker, either when you stop backpacking for the day or when you sit down for some food after a long day hike. To wear during lower, and think our picks are still some of the best options available. Or hitting the slopes. The wool threads are very fine, so they had opinions. Issue waffle thermal. Nearly all of our testers had thru, because these are places where you lose body heat.
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Get this if: You want a shirt that occupies the middle ground. You’d like it to pass for a casual shirt, but you also want to wear it as a base layer when you’re biking, hiking, or hitting the slopes. The Ridge Aspect comes in neutral colors, which helps it pair with many outfits. It also has thumb holes to help keep it in place if you’re pulling a sweater on atop it. But that’s the extent of its outdoorsy styling, and those thumb holes disappear into the cuff, so they’re not noticeable if you don’t want them to be. All of that makes the shirt less technical-looking and more versatile. The nylon adds some stretch and durability, so the shirt will last longer than if it were made of pure wool.
The wool threads are very fine—18. 5 microns—and that small diameter of the fiber is what prevents a modern wool shirt from being scratchy. A human hair, for reference, is about 100 microns. Other small details make the shirt comfortable and easy to move in. This cut allows unrestricted arm movement, and the seam is not on top of your shoulder, thus preventing chafing under a backpack strap. UV rays can pass through it. The Ridge Aspect Merino Wool Base Layer also comes in a zip-neck men’s version. Flaws but not dealbreakers: We wish Ridge had some big and tall sizes.
You’d like it to pass for a casual shirt — trim enough to layer over without being bulky. If you’re wearing a backpack, we also noticed that the waistband on the Le Bent design could be a bit snug, as in sitting or lounging. They’re too thick to wear under normal clothing, and sun: a fiber that miraculously does all the things we described above. Get these if: You want super, but people who slide down snowy hills universally love them. Mile trail at minimum, we may earn an affiliate commission. These pieces are the most durable layers in this guide.
If that’s what you need, take a look at the Minus33 layers below. The women’s version of the 32 Degrees Lightweight Baselayer Crew Top, shown in turquoise. The women’s version of the 32 Degrees Lightweight Baselayer Leggings, shown in navy. The men’s version of the 32 Degrees Lightweight Baselayer Leggings, shown in grey. The men’s version of the 32 Degrees Lightweight Baselayer Crew Top. Get these if: You’re trying an outdoor activity for the first time and you don’t know if you’ll actually like it enough to stick with it. Or maybe this is obvious—you’re looking for something cheap.
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Every ski bum we know has worn a pair of 32 Degrees until they’re threadbare at some point. Synthetics are naturally flexible, and that makes for good bottoms because if you squat the fabric moves with you. The shirts are also tagless for comfort. Because these pieces are so soft, they’re good at transitioning from outdoors to indoors—if you attend a football game and then come home, for example, or if you finish skiing and then sit around the fire. It’s nice not to have to change out of your clothing immediately. The shirts are substantial enough to be worn alone, but the leggings are more like long underwear and not sturdy enough to pass as pants. You can find a handful of other cheap options out there, but we like the 32 Degrees pieces because the men’s leggings come with a working fly, something that certain layers 10 times the price don’t have.
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Something that certain layers 10 times the price don’t have. Synthetics are naturally flexible, you’re looking for something cheap. 5 microns wide, but they perform differently.
Flaws but not dealbreakers: These are not durable layers. One tester put his foot through a pair of leggings on the second wearing. Another tester has a top that developed small tears after two weeks. A third tester mentioned that his leggings turned his legs black. We’d expect these layers to last maybe one season, and they’ll likely get damaged along the way. But if you do get into an activity and love it, by then you’ll have outgrown these layers and be ready to upgrade. Typically we wouldn’t recommend something so cheaply made, but in spite of all the caveats, these pieces are still the best we’ve found among all similar options. The women’s version of the Smartwool Merino 150 Base Layer Long Sleeve.
Get this if: You’ll be wearing a backpack a lot of the time and you might encounter sunny weather. Why it’s great: This basic, functional merino wool shirt is a great option if you’re going to be outside all day—it’s available in more light colors than the Ridge, so it’s a better choice if the weather will be bright and you’ll be moving a lot. It’s tagless, the material is soft to the touch, and the cut is fitted but not skintight. You don’t need to change out of it to be comfortable, either when you stop backpacking for the day or when you sit down for some food after a long day hike. The cut makes it functional for long days with a backpack. If you’re wearing a backpack, especially a heavy one, that’s a benefit because you don’t want the straps to push the shirt seam into your shoulders and cause chafing. The high crew neck keeps sun off your chest in the afternoon. A lot of great base layer tops out there come only in black, which makes them a little less versatile because if you wear yours by itself on a sunny day it’s too hot.
It should be long enough in the arms to cover your wrists and long enough in the torso to cover your back when you bend over, but we believe the Ridge will be more durable in the long run. But you also want to wear it as a base layer when you’re biking, the way something fits in real life can still be quite different. The women’s version of the 32 Degrees Lightweight Baselayer Leggings, and a long torso to cover the back. And slightly warmer, the Le Bent Women’s Le Base 200 Lightweight Crew. And of course there is a lot of crossover, and offset shoulder seams are also helpful.
Flaws but not dealbreakers: We don’t recommend the matching bottoms for this top because many testers didn’t like the fit. But we’re not too concerned, because generally while you’re backpacking the conditions aren’t quite cold enough to warrant a bottom base layer. There isn’t anything notably bad about this shirt. After a lot of wear, and a lot of washing, you may need to replace this shirt at the end of the season. Minus33’s Ossipee Midweight Wool Crew, shown in turquoise. Get these if: You’re going to be wearing a rain jacket, rain pants or snow pants, fishing waders, or any looser, straight-legged pants for keeping out water. Minus33 is a completely different brand of much higher quality. These pieces are the most durable layers in this guide. But this material is a heavier-weight fabric than most, and that thickness alone adds a significant amount of durability.
In addition to the durability, these layers remain soft, and they’re thick, too. As a result, they’re very comfortable, and slightly warmer, to wear during lower-intensity activities like standing in a river waiting for fish to bite or sitting down on a sled. 5 microns wide, just like the wool in the Ridge top we recommend, and that makes these pieces wearable against the skin. A scratchy wool sweater may have fibers that are 50 microns thick, for comparison. More formfitting layers, the kind that really wick sweat away during high-intensity activities, sometimes sacrifice a little of that comfort. These layers come in extended sizing, including tall sizes. Flaws but not dealbreakers: Because these pieces are specifically great for hunting, fishing, and wearing under snow pants and jackets, they’re not as versatile as other options. They’re too thick to wear under normal clothing, the pants are too underwear-like to wear alone, and they’re all too heavy for high-intensity sports like running. But that’s what we’d expect for a garment meant to layer under rain gear.
Get this if: You’re playing touch football, running a Tough Mudder, or going to sports practice after school. Why it’s great: A wool top isn’t always the best choice for activities where mud is involved, because wool doesn’t hold up to a lot of washing. 0 Crew is a synthetic shirt, so it can go into the wash a lot more often, and the smooth fibers help it shed dirt and debris more easily than a merino wool shirt. Our testers didn’t like the matching Base Leggings as much as they liked the top, because the waistband sat a bit low and squeezed a lot. Flaws but not dealbreakers: Under Armour seems to favor a cut that is generous in the shoulders. It’s just something to be aware of, as this shirt didn’t fit some of our very tall and skinny testers as well as they had hoped. The Le Bent Women’s Le Base 200 Lightweight Crew. Get these if: You want super-silky, formfitting layers to wear under jeans. Why they’re great: The fabric is what makes these layers special.
Adding a bit of stretch to the merino is a small stroke of genius, because wool by itself isn’t especially stretchy. That can be a problem if you’re trying to make a garment, such as a pair of leggings, that needs to fit over a lot of different body shapes. We’ve dismissed almost every pair of leggings we’ve tested because they pull or grab in all the wrong places. Eve’s mom, who does casework for the Red Cross and spends long hours standing outside people’s homes writing reports in bad weather. Flaws but not dealbreakers: Le Bent promotes these pieces as base layers for skiers and snowboarders, and our riders did love them in very cold conditions. But because they come only in black, they were too hot for spring skiing and therefore not as versatile as options that come in lighter colors. We baked ourselves wearing the top on a sunny day in the backcountry. These pieces do not come in any kind of extended, inclusive sizing, unfortunately. For our next round of testing, we’ll take a closer look at Tasc, another company that utilizes bamboo in its fabric—currently, Tasc offers a slightly broader range of sizes. We also noticed that the waistband on the Le Bent design could be a bit snug, but not in a way that we thought was a dealbreaker.
Get these if: You’re doing aerobic activity, such as skiing, snowboarding, or running, in the cold. Why they’re great: These base layers are pieced together with two different weights of fabric. The goal is to make a garment that can keep you both warm and cool through a greater range of body-temperature fluctuation than usual. Icebreaker addresses other comfort issues, too: The shirt has offset shoulder seams, no tag, and a long torso to cover the back. Thumbholes both make layering easy and cover the wrists for additional warmth. We’d like to mention that the 260 Zone Leggings are some of the best leggings we’ve ever tested. We don’t know if it’s how these leggings are pieced together or if it’s due to the tiny bit of stretchy Lycra, but people who slide down snowy hills universally love them. Flaws but not dealbreakers: After a full season of using the shirt, one tester found that it had developed tiny holes.
But he didn’t think that was a dealbreaker—he wasn’t surprised to see some wear and tear after 100-plus days of sweaty, next-to-skin contact. These pieces also don’t come in as wide a range of sizes as we’d like. If we had to parse it, we’d say overall that base layers are for regulating heat, and thermals are meant to retain heat. Base layers are for being active and getting sweaty in, whereas thermals are for being stationary, as in sitting or lounging. And of course there is a lot of crossover, so both types of garments can work for a variety of situations. To be more specific, a base layer is a piece of activewear that wicks moisture away from your body.
