Best Long Underwear · #7
Super Thermo Mesh
Brynje
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The Norwegian mesh string layer — bizarre-looking, unmatched moisture handling in deep cold.
Pros
- Unmatched moisture wicking in high-exertion, cold environments
- Creates excellent insulating air pocket when layered properly
- Exceptional warmth-to-weight ratio for its category
- Quick-drying properties prevent chilling
- Surprsiingly durable for its open-knit construction
Cons
- Unconventional appearance, not suitable as a standalone layer
- Requires proper layering to maximize insulation benefits
- Polypropylene can retain odors if not washed promptly
- Not ideal for casual wear or low-output activities
- Can feel slightly abrasive to some sensitive skin types
Best uses
- Backcountry skiing
- Winter mountaineering
- Ice climbing
- Cold weather hunting
- High-output winter sports
Specifications
- Maker
- Brynje
- Model
- Super Thermo Mesh
- Material
- Polypropylene Mesh
- Construction
- Open Mesh Knit
- Weight Class
- Lightweight / Midweight Layering
- Best For
- Deep Cold, High Output
Pricing
We don't publish a price we haven't verified. The retailer links below open the live listing for this exact model.
Best for
Backcountry skiing, Winter mountaineering, Ice climbing, Cold weather hunting, High-output winter sports
Where to buy the Super Thermo Mesh
Prices and stock change often, so check the current Amazon offer before you buy.
Some links are affiliate links. Buying through them supports our testing at no extra cost to you.
The Brynje Super Thermo Mesh long underwear, a rather distinctive offering from Norway, secures its place on our list not by being a jack-of-all-trades, but by excelling in a very specific niche: extreme cold weather and high-exertion activities. Its unique, open-weave mesh construction, which often elicits an eyebrow raise or two, is fundamentally different from traditional solid-knit base layers. This isn't your average cozy thermal; it's a meticulously engineered system designed for maximum thermal regulation when conditions demand it most. It's a prime example of form following function, where the unconventional appearance directly translates to superior performance in specific scenarios. While its aesthetics might be an acquired taste, the Super Thermo Mesh's real genius lies in its ability to manage moisture and create an insulating air pocket next to the skin. This isn't about trapping warmth in a conventional sense, but rather about rapidly moving sweat away from the body while simultaneously providing a breathable barrier. It's a tool for serious outdoor enthusiasts who understand the critical importance of staying dry in cold environments, and who prioritize performance over plush comfort. If your adventures involve significant temperature swings, intense output, and the risk of chilling, this layer warrants serious consideration.
Who It's Really For
This layer isn't for casual strolls or cabin lounging. It's purpose-built for those pushing hard in genuinely cold conditions – think ice climbing, backcountry skiing, winter mountaineering, or cold-weather hunting. It shines when you're alternating between high exertion, where you generate significant body heat and sweat, and periods of lower activity or rest, where the risk of chilling is high. If you find yourself consistently clammy and cold in traditional base layers during demanding winter pursuits, the mesh design offers a solution to that specific problem. It's a piece of technical gear for serious users who understand layering systems.
Materials & Construction
The Super Thermo Mesh is constructed from 100% polypropylene, chosen for its hydrophobic properties. Polypropylene doesn't absorb moisture, meaning it excels at wicking sweat away from the skin. The defining feature is its distinctive open mesh knit. This isn't a solid fabric; it's a grid of interconnected threads that creates thousands of tiny air pockets. This construction provides two primary benefits: maximum surface area for moisture evaporation and a highly efficient way to trap insulating air when an outer layer is added. It's a minimalist approach to thermoregulation that prioritizes performance over bulk.
Real-World Performance
In the field, the performance of the mesh is remarkably consistent with its design intent. When you sweat, moisture is rapidly pushed through the mesh and into your next layer, keeping your skin surprisingly dry. This prevents the clammy, chilling sensation common with saturated base layers. When layered, the air pockets within the mesh create an incredibly effective thermal barrier, often feeling warmer than solid fabrics of similar weight. It thrives in dynamic environments where temperature regulation is critical, preventing both overheating during exertion and chilling during rest periods. It’s an effective system, provided it's worn correctly with appropriate mid and outer layers.
Weight & Packability
Given its open structure, the Super Thermo Mesh is exceptionally lightweight and surprisingly packable. It compresses down to a very small size, making it an easy addition to a winter pack without adding significant bulk or heft. For the thermal performance it provides, its weight-to-warmth ratio is outstanding. This makes it an attractive option for gram-conscious adventurers who still need serious protection from the cold. Its light weight also contributes to its overall comfort during high-output activities, as it never feels restrictive or heavy on the body.
Durability & Longevity
Despite its delicate appearance, the polypropylene mesh is quite durable. The material itself is robust, and the knit, while open, resists snags and tears better than one might expect. I've put these through multiple seasons of hard use, and they hold up well with proper care. Like all polypropylene, it's susceptible to damage from high heat (avoid the dryer) and can retain odors more readily than merino wool if not washed promptly. However, with appropriate laundering, a set of Super Thermo Mesh can provide years of reliable service in harsh conditions.
How we chose
We started with a long list of best long underwear that people actually buy, cut anything that could not clear our baseline for durability and field performance, then ranked the 10 that were left against the same criteria. Rankings are editorial. No brand pays for placement, and affiliate links never move a pick up or down.
- Real-world durability
- How the material, stitching, or steel holds up after a season of hard use — not how it looks new.
- Performance in bad conditions
- Wind, rain, cold, and grit are the test. Anything that only works on a nice day gets marked down.
- Weight and packability
- Every ounce has to earn its place in the pack, but not at the cost of something that fails in the field.
- Ease of use
- Setup, adjustment, and maintenance with cold hands, in the dark, without the manual.
- Value at its price point
- Compared against the closest competitors in the same tier, not against cheaper gear in a different class.
- Repairability and support
- Field-fixable design, available parts, and a warranty the maker actually honors.
Super Thermo Mesh — frequently asked questions
- Is the Super Thermo Mesh worth it?
- We rank it #7 in Best Long Underwear. The Norwegian mesh string layer — bizarre-looking, unmatched moisture handling in deep cold.
- What is the Super Thermo Mesh best for?
- Best for backcountry skiing, winter mountaineering, ice climbing and cold weather hunting. Standouts: unmatched moisture wicking in high-exertion, cold environments and creates excellent insulating air pocket when layered properly.
- What are the downsides of the Super Thermo Mesh?
- Unconventional appearance, not suitable as a standalone layer, Requires proper layering to maximize insulation benefits and Polypropylene can retain odors if not washed promptly.
- What are the key specs of the Super Thermo Mesh?
- Maker: Brynje · Model: Super Thermo Mesh · Material: Polypropylene Mesh · Construction: Open Mesh Knit · Weight Class: Lightweight / Midweight Layering
- Who It's Really For?
- This layer isn't for casual strolls or cabin lounging. It's purpose-built for those pushing hard in genuinely cold conditions – think ice climbing, backcountry skiing, winter mountaineering, or cold-weather hunting.
- Materials & Construction — what should I know about the Super Thermo Mesh?
- The Super Thermo Mesh is constructed from 100% polypropylene, chosen for its hydrophobic properties. Polypropylene doesn't absorb moisture, meaning it excels at wicking sweat away from the skin.
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