Best Base Layer of 2025

Reasons to Buy

• Made from super comfortable merino wool
• Effective at wicking moisture and keeping dry
• Moderately warm while staying lightweight
• Resilient material offers good durability
• Highly resistant to odor

Reasons to Avoid

• On the pricier end of the spectrum
• Fit may be a tad too tight for some users
• May not provide enough warmth in very cold conditions without extra layers

Packed with performance and superb comfort, the Smartwool Merino 150 Base Layer has proven to be an all-rounder in our test. Made from 87% Merino wool and 13% nylon core, it's jam-packed with features to keep you comfortable during your outdoor adventures.

Buyers have frequently noted the supreme comfort of the Smartwool Merino 150 Base Layer. The fabric is super soft, and its luxurious feel against the skin is a definite highlight. What's even better is the stretchiness provided by the small percentage of nylon, making it a hit for those looking for flexibility in their base layer.

The breathability and temperature regulation of this garment is highly impressive. Customers have noted its effectiveness in a wide variety of climates. Whether you're taking a summer hike or a winter climb, it appears to do well in maintaining optimum body temperature and reducing overheating.

An added bonus is its odor resistance, which is a prominent feature of merino wool. Several buyers have left rave reviews commenting on how fresh it kept them even after hectic activity. Some have even used it on multi-day adventures without experiencing any unpleasant smells.

However, not all reviews of the Smartwool Merino 150 Base Layer are glowing. Some users have mentioned concerning durability issues, claiming that after a few uses the fabric showed signs of wear and tear. Pilling and holes seemed to be the most common complaints, so long-term toughness might be a potential downside.

A few customers are not thrilled with the fit. They describe it as a bit loose, especially around the waist and arms. Consequently, this may remove its efficiency as a snug base layer that's supposed to stick close to the user's body.

That being said, the majority of users highly praise this base layer, particularly for its comfort, breathability, odor resistance, and temperature regulation properties. So, if you're after a high-performing, comfortable, and largely durable base layer, the Smartwool Merino 150 Base Layer might just be the ticket you need for your outdoor escapades.

Reasons to Buy

• Excellent fit and comfort
• Great for moisture management
• Quality material
• Provides good warmth
• Highly versatile

Reasons to Avoid

• A bit pricey
• Lacks odor resistance compared to some competitors
• Not as breathable as some alternatives

Arc'teryx, the well-known brand for outdoor gear, does a great job with their Rho LT Hoody in creating a functional and versatile base layer that also delivers on style. Its synthetic fabric offers a nice blend of warmth, breathability and moisture-wicking capabilities, fulfilling your various needs whether you're hiking up a mountain or simply going for a walk on a chilly day.

One thing that online reviewers frequently comment on is the base layer's durability. The Rho LT Hoody uses Arc'teryx's patented Torrent™ material, making it resilient against regular wear and tear. So whether you're crawling through rock tunnels or weaving through the woods, you won't have to worry about it falling apart on you.

What people also seem to love is the fit. It's snug enough to keep you warm but not too tight that it restricts your movement. It's like having an additional layer of skin, and it's hardly noticeable once you're all geared up. The hoody also has thumbholes to keep your sleeves in place, which has been a delightful feature for many users.

In terms of comfort, the Rho LT Hoody is soft and smooth against the skin. Reviewers note that even after extended periods of wear, there wasn't any chafe or discomfort, which is definitely a huge plus.

However, as much as people like the Arc'teryx Rho LT Hoody, it does have its downsides. Reviewers note that the lack of a zipper can become inconvenient at times, as you might struggle with ventilation when you start to heat up from your activities. The lengthy drying time has also been another point of contention among users.

Moreover, the premium price tag is a deterrent for some, making it a serious investment piece. However, many reviewers opine that this is a case of 'you get what you pay for', as the quality is reflected in the cost.

Overall, while some users had issues with the lack of convenient features and expensive cost, the Arc'teryx Rho LT Hoody appears to be a hit among users for its durability, comfort, and fit especially for active outdoor folks who aren't afraid to shell out a bit more for top-notch quality and design.

Reasons to Buy

• High-quality merino wool construction
• Excellent moisture-wicking properties
• Great warmth-to-weight ratio
• Comfortable fit and design
• Durable for long-term use
• Resistant to odor

Reasons to Avoid

• Might be a bit pricey for some
• Not the most breathable option out there
• Fit may not suit everyone's preference

The Black Diamond Solution 150 Merino Half Zip Hoody stands out in the crowd of base layers. Unlike many winter gear, this hoody balances warmth, breathability, and comfort with aplomb.

Designed with NuYarn technology, it is made from 78% merino wool and 22% polyester. This combo results in a high-performance hoody that provides both incredible warmth and effective moisture wicking. It's a piece you can rely on whether you're hiking through mountains, rock climbing, or setting up camp.

One of the marketing points Black Diamond emphasizes is the hoody's odor resistance. Merino wool is renowned for its anti-microbial properties, which help keep those unpleasant odors at bay during a long outdoor trip. Buyers have found this claim to be true in their experiences, indicating that even after several days of use, the hoody remained fresh.

Functionality aside, what many users appreciate is the hoody's style and fit. With a sleek design and varied size options (from S to XXL), it's attractive yet unassuming. The fit is athletic, suggesting a tailored feel but still providing ample space for light layering underneath.

Customers appreciate the thoughtful design. The half zip feature allows for temperature regulation, and the thumbhole cuffs increase warmth by keeping the sleeves down and stopping heat from escaping. The hoody also sports a chest pocket - a feature praised by users for its convenience.

Durability is where some users had concerns. A few reported minor issues, such as early wear in high friction areas or slight pilling after washing. However, these were not widely reported occurrences and did not detract from the overall functionality of the garment.

The conversation around price is fair. While not the cheapest on the market, users agree that it's a valuable investment for those regularly braving the elements due to its undeniable quality and performance.

Reasons to Buy

• Affordable without compromising quality
• Lightweight yet warm
• Effective moisture-wicking
• Odor-resistant fabric

Reasons to Avoid

• Can feel tight for some users
• Not as durable as some pricier options
• Fabric might be less breathable

The REI Co-op Lightweight Baselayer Crew Top Long Sleeve is definitely a great find for those who love the great outdoors but are on a budget. This base layer top is not just affordable, it also provides excellent value for the money spent. Coming in a solid neutral color and a simple, sleek finish, it's a good match for any outdoor gear.

People who bought this product appreciated its lightweight design. Weighing in at just over half a pound, this base layer is featherlight and can be easily stuffed into your backpack without making it unnecessarily heavy. The lightweight nature enables it to also act as an excellent layering piece without adding bulk or reducing mobility.

Users have also reported that the top effectively keeps you warm when the temperature drops and reasonably cool when it gets warmer. It's great at wicking away sweat, and this helps to prevent the shivers that can sometimes happen after intense activity.

The REI Co-op Lightweight Baselayer Crew Top Long Sleeve also gets a thumbs up for its durability. Users report that it can withstand regular use and even rough treatment. It has proven to be resilient, maintaining its shape and function even after multiple washes.

One downside mentioned by a few users was that the sizing can be a bit tricky. Some users reported that the top ran a bit small, so you might want to order a size larger than you usually get. However, there’s a consensus that once you get the size right, the fit is great and the top is comfortable for all-day wear.

Another minor complaint from some users was regarding the collar. They pointed out that it can be a little tight when fully buttoned up. This might be a downside for those who need the complete coverage during colder months.

Overall, customers generally feel that the REI Co-op Lightweight Baselayer Crew Top Long Sleeve is a solid choice for an outdoor enthusiast on a budget. From its durability, warmth, and moisture-wicking properties, to its comfort and lightweight nature, it has all the basic necessities that a good base layer should have. While there are some minor sizing and collar issues, they don't overshadow the many beneficial features that this top offers.

Reasons to Buy

• Superb insulation and warmth
• Excellent breathability
• Durable and robust material
• Perfect fit with great layering compatibility
• Comes with moisture-wicking feature
• Fairly odor resistant

Reasons to Avoid

• Relatively pricey
• May be too warm for mild weather
• Limited color options

The Arc'teryx Rho Heavyweight Zip Neck is a top notch base layer for men, and it's great for braving those icy winds up on the Alps or keeping toasty during those winter hikes. It's got some pretty impressive muscle in the warmth department. While it comes with a bit of a price tag, most people reckon it's worth every penny, especially if you're looking for something that'll keep you warm when the mercury drops to 'I-can't-feel-my-toes' levels.

This base layer boasts a bit of a techy fit. It's snug and form-fitting, which is exactly what you want from a base layer. By hugging tight to the body, it keeps the heat in and the cold out, serving as an excellent thermal layer. This tight fit might not be everyone’s cup of tea, so it's worth checking it out in-store if you're unsure.

The fabric is where this baby really shines. Arc'teryx have built this with Polartec® Power Stretch®, tipping the hat towards long-term durability and stretchability. It's got a nice soft feel against the skin, too. It scores full marks in the comfort column, and users find it gentle even during prolonged use.

The zip neck design is a handy addition, facilitating extra airflow when you need it. Useful for when those treks start heating you up more than you anticipated.

On the downside, the Rho Heavyweight has been reported to snag a bit. Some users noted the fabric can catch on sharper objects, which is not ideal if you're planning to be grappling with rocks.

Despite being heavyweight, this base layer is surprisingly breathable. That being said, a few reviewers have commented that the breathability can suffer if heavily layered or under intense activity. A trade-off for that extra warmth, perhaps.

Arc'teryx has invested in some serious comfort-feature. No itchy tags or poking seams here, folks, thanks to hybrid mapping of fabrics and a no-lift gusseted underarms design.

As far as durability, it's seen as pretty rugged. There were a couple of mentions of stitching issues over time, but nothing too concerning. Overall, lots of people who've bought this product have it down as a reliable long-term investment.

To sum it all up, the Arc'teryx Rho Heavyweight Zip Neck certainly earns its spot as a top-of-the-range base layer. It might leave a bit of a dent in the wallet, but for serious outdoor enthusiasts, staying warm, comfy and active in colder climates might just be priceless.

Reasons to Buy

• Superb warmth and comfort
• Excellent moisture-wicking properties
• Highly breathable
• Odor-resistant fabric
• Durable and long-lasting

Reasons to Avoid

• Price is a bit steep
• Takes longer to dry compared to some synthetic base layers
• Might be too warm for high-intensity activities

The Smartwool Merino 250 Base Layer Crew is a top pick for those hitting the slopes or chilling at the resort. This base layer offers a comfy fit which many users have appreciated. It's made from 100% Merino wool and is designed to provide an optimal combination of breathability, insulation, and comfort.

When shoppers online talk about the Smartwool Merino 250, they often mention its high quality and superb warmth. It appears this base layer has a knack for keeping you warm, even in those frosty mountain conditions. Many love how it successfully traps body heat, making it an awesome choice for colder climates or for those of us who are always freezing.

But let's talk about comfort because that's where this brand really outdid itself, according to the reviews. It seems the Smartwool Merino 250 is super smooth to the touch and doesn't come with any itchy feeling that other wool products might. People also rave about how well it fits, not too tight, not too loose, just that perfect, snug fit to keep you cozy.

As for durability, opinions in reviews seem to vary, but most people agree that it stands up pretty well to regular use. However, a few folks noted some wear and tear after repeated washes -- but hey, we all know that wool can be a bit tricky to care for.

Another point that pops up regularly in reviews is the price tag, with some finding it a bit on the steep side for a base layer. But, in the grand scheme of things, it seems most agree that the comfort, insulation, and fit make it a worthy investment.

Ultimately, the Smartwool Merino 250 stands out from the pack with raving reviews from users loving its combination of warmth, comfort and fit. So, if you're in the market for an upper body base layer to keep you snug on the slopes or while hanging out at the resort, it seems like this is a great contender.