How to Choose Base Layers
REI Co-op Heavyweight Merino Long-Sleeve Base Layer Crew Top - Men's
$99.95
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Get ready for adventures in the cold with our warmest merino wool base layer yet. Made with 100% merino wool, the men's REI Co-op Heavyweight Merino Long-Sleeve Crew top is supersoft on the skin.
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- Heavyweight 250 g merino wool offers a soft feel without the scratchiness
- Made with 100% merino wool that naturally wicks away sweat, resists odors and dries quickly
- UPF 50+ sun protection
- Underarm gussets are made for ease of movement
- Shoulder seams are rolled forward to help prevent chafing under pack straps
- Close-to-body fit for optimum performance
- Back length: 28.5 in.; Tall sizes: 30.5 in.
- Weight for size M: 9.9 oz. (280 g)
- Locker loop makes it easy to hang this shirt to dry or just keep it off the ground
- Machine wash cold, use wool wash product, do not twist or wring, remove promptly; do not bleach; tumble dry low
- REI Co-op brand is certified to The Climate Label; we actively fund efforts to reduce carbon emissions across our business and support climate projects around the world
- Made in a Fair Trade Certified™ factory
Imported.
View all REI Co-op Men's Base Layer Tops| Best Use | Multisport |
|---|---|
| Shirt Type | T-shirt |
| Fabric | 100% merino wool |
| Sun-Protective Fabric | Yes |
| UPF Rating | 50+ |
| Moisture Wicking | Yes |
| Quick Drying | Yes |
| Underwear Weight | Heavyweight |
| Sleeve Length | Long Sleeve |
| Gender | Men's |
| Sustainability | Fair Trade Certified™ factory From a Climate Label Certified brand |
REI Co-op Clothing - Men's
| XS | S | M | L | XL | XXL | XXXL | 24 IN Waist | 26 IN Waist | 28 IN Waist | 30 IN Waist | 31 IN Waist | 32 IN Waist | 33 IN Waist | 34 IN Waist | 35 IN Waist | 36 IN Waist | 38 IN Waist | 40 IN Waist | 42 IN Waist | 44 IN Waist | 46 IN Waist | 48 IN Waist | 50 IN Waist | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chest | 35 | 36 - 38 | 39 - 41 | 42 - 45 | 46 - 49 | 50 - 53 | 54 - 57 | |||||||||||||||||
| Sleeve Length | 32 | 32.5 | 33 | 33.5 | 34 | 34.75 | 35.5 | |||||||||||||||||
| Waist | 27.5 | 28 - 30 | 32 - 34 | 36 - 38 | 40 - 42 | 44 - 46 | 48 - 50 | 24 | 26 | 28 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 38 | 40 | 42 | 44 | 46 | 48 | 50 |
| Hip | 33.5 | 34.5 - 36.5 | 37.5 - 39.5 | 41 - 43 | 44 - 46.5 | 47.5 - 50.5 | 51.5 - 54.5 | 32 | 33.5 | 34.5 | 36.5 | 37 | 37.5 | 38.5 | 39.5 | 40.25 | 41 | 43 | 44 | 46.5 | 47.5 | 50.5 | 52.5 | 54.5 |
| Inseam | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 |
Sizing Notes
Measurements are stated in inches unless otherwise indicated. Size chart values represent body measurements, not garment measurements.
SHORT: Some pants are available in short sizes, which generally means an inseam that is 2.5 inches shorter than regular sizes.
TALL: Some pants, shirts, jackets and parkas are available in tall sizes, which generally means an inseam that is 3 inches longer and a rise that is 1 inch longer, a shirt or jacket body that is 2 inches longer, a parka body that is 2.5 inches longer and sleeves that are 2.5 inches longer than regular sizes.
Capri or cropped pants have an intentionally shorter inseam—reference the technical specs instead of this chart.
Inseam is measured to the floor.
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Most Helpful Favorable Review
Fall or Spring hiking
Luke9 months ago
Received free productThis is a fairly heavy long sleeve hiking shirt meant for use as a base layer in winter, or as an outer layer during the fall or spring time when the weather is cold. It's made of Merino wool, so it'll keep you warm even if you sweat or it gets wet. It has a soft, breathable feel, and felt comfortable against my skin. The material was comfortable enough to wear in 50 degree weather without any jacket or anything. The fit was great too, I'm 5'9'' with a muscular build, and it was perfectly sized for me, not too baggy, not too tight.
LukeReceived free product
Cleveland, Ohio
10 people found this review helpful
Most Helpful Critical Review
Its only 250g and labeled as "Heavyweight"
kd_ca8 months ago
Its 250g and labeled as "Heavyweight". Looking at other merino wool products 250g is midweight. I don't know if the labeling is a mistake.
kd_ca
5 people found this review helpful
Customer Images
StewBe
Received free product
Denver, CO
Merino Base Jumping Into The Hiking Wardrobe
8 months ago
Overall, this is a very nice base layer to add to anyone's outdoor wardrobe. A few thoughts after taking it out for a few spins. - Initial impression is how nice the material feels to the touch. Merino wool is a great material but two major concerns come to mind when it comes to wool. How it feels next to the skin given this is suppose to be a base layer and the level of laundry matenance required. Having this being the initial layer actually felt quite comfortable. No itching or even static comes to mind after wearing around both outside or as a casual wear inside. So the worry about sking contact was actually a positive. As far as maintenance, a base layer that is used for outdoor activities should not require anymore thought than all of the other sporting garments when it comes to laundry. It was treated as such. The laundry care called the shirt to be washed in cold and pulled immediately and tumbled low. Wash in warm and tossed in the dryer with everything else is what happened with this one. Overall, it came out just fine. Wrinkles or shrinking weren't a problem. Only issue noticed pertained to the 'collar'. The collar seam bunched up some by not allowing the material to lay flat. If one is wearing the shirt as casual wear around town, it might be an issue. If using the shirt for outdoor fun, you won't think about it. - Next test was the fit of a size large. I'm 5' 9" and average build. The shoulders worked well and the sleeve was a little long. Longer sleeves is better than shorter ones in base layers so that was a plus. The overall length was too long and it didn't have a tappered cut so it was boxy. Again, not a big deal with base layers and allows more play for the winter pounds if that's a concern. I'd probably grab a medium next time and deal with the tighter shoulder/chest. - Next test was it's warmth. Sporting this on a few days around 50 degrees seemed a better trial. Putting a layer under a coat hides problems nor believing it's going to keep one warm under 45 might be asking too much. The shirt by itself is warm enough to a point I was not thinking about the temp at all. And it was thick enough where a mild breeze didn't penetrate. It performed great. Final thoughts: - Very comfortable and performed better than expected as an only layer making it a good casual wear on cold days. - Can be low maintenance care if one isn't worried about the bunching in the collar seam. - Extremely nice as a base given the performace of warmth without absorbing sweat and is fantastic under a coat for skiing, hiking, etc - It would be nice if it were tappered at the waist
Age:45–54
Weight:175–200 lbs.
Height:5'9"
Yes , I recommend this product
Sawatch ultra
Received free product
Salida, CO
Super soft, comfortable
8 months ago
I received this product for free from REI for an honest review. I wore this base layer in nearly all the situations that I think I'd use something like this - moderate exercise around the neighborhood, lounging around the house, skiing, etc. This most closely compares to a 250 merino base layer that I've primarily used for skiing for years now. Overall, I found this to be buttery soft and wick moisture very well. For its weight, it keeps me pretty warm. It doesn't quite compare with the 250 shirt in terms of warmth, but it's also not as thick. I find myself wearing it a lot more and using it in a wider variety of activities because it's so soft and comfortable. I'd call it a buy unless you need something thicker for the non-bluebird days. Model is 6'0", 135 lbs. middle aged, and wearing a size medium.
Age:35–44
Weight:125–150 lbs.
Height:6'0"
Yes , I recommend this product
ernest l
Received free product
Washington State
As warm as they get
8 months ago
The shirt has a heavier feel than the Smart wool but it's not a bad thing. Worn with a hoodie and a rain jacket it provides a good amount of warmth without being overwhelming. I tested this out during an outdoor walk with low temps and light rain wearing a rain resistant puffy jacket. It was a little much when I was walking at a strong pace but when I stopped it kept me nice and warm. The sleeve length is also very nice. It keeps my wrists covered when sitting down. The shirt also doesn't rise too much when I move my arms above my head.
Age:45–54
Weight:175–200 lbs.
Height:5'9"
Yes , I recommend this product
Luke
Received free product
Cleveland, Ohio
Fall or Spring hiking
9 months ago
This is a fairly heavy long sleeve hiking shirt meant for use as a base layer in winter, or as an outer layer during the fall or spring time when the weather is cold. It's made of Merino wool, so it'll keep you warm even if you sweat or it gets wet. It has a soft, breathable feel, and felt comfortable against my skin. The material was comfortable enough to wear in 50 degree weather without any jacket or anything. The fit was great too, I'm 5'9'' with a muscular build, and it was perfectly sized for me, not too baggy, not too tight.
Age:35–44
Weight:150–175 lbs.
Height:5'9"
Yes , I recommend this product
David W
Received free product
Eugene, OR
My new favorite layering piece
8 months ago
I wore this shirt every day the first week I had it - inside lounging around, by itself outside on some sunny cool days, and as a base layer with something to break the wind on colder days. It offered good temperature regulation I've come to expect from lighter weight wool layers. I was honestly impressed by how soft and comfortable the fabric was new, and it's continued to feel good after washing. It's hard to believe it's 100% merino wool, because I don't detect any wearing wool skin feel that I'm used to from "No itch" wool clothing. I didn't notice any seam lines, or hot spots on my shoulders after wearing a backpack over this shirt. I haven't seen a shirt with this style seams before, but I'm a fan so far. I'm intending to get another one of these in this weight, and if there is a similar fit light weight I'll snag those as well. In black this weight shirt is going to be too warm for summer use, but breathability and quick drying I'm expecting to use it all 3 other seasons.
Age:45–54
Weight:200–225 lbs.
Height:5'11"
Yes , I recommend this product
Bill B
Received free product
Milwaukie, OR
Warm wool base
8 months ago
The REI Heavyweight Merino Long Sleeve Basel ayer is a nice, heavier weight wool baselayer. Compared to the lighter weight merino wool base layer REI makes, this one is substantially more robust in construction and weight. Seams are flatlock stitched, providing for a smooth feel against the skin. This shirt also has a nice drape to it, and fit well while wearing. I am 5’9” and 155 pounds and wore the medium. I could probably have gone with a small had I wanted a body-hugging fit. The weather this fall has been warm, so it is difficult to say how this will ultimately perform in colder weather. But for when I have worn it thus far (with temps in the 50s), I have stayed warm without needing heavier, extra layers. So, I would anticipate this base layer will perform excellently in the cold. The shirt compares well to similar offerings from other manufacturers, and is certainly competitively priced as REI always does. I would not hesitate to recommend it if you are looking for a heavyweight base layer for the colder months of the year in your active pursuits.
Age:45–54
Weight:150–175 lbs.
Height:5'9"
Yes , I recommend this product
Dale
Received free product
Wisconsin
Comfortable Base Layer/Just Right Amount of Snug
8 months ago
I've used this base layer a number of times now and it definitely has kept the chill out while working and hiking outside. Warm enough that I've used this base layer just by itself when above freezing. My favorite thing though about this base layer is the fit. All my other base layer shirts fit so tightly. This one is just the right amount of snug without being completely form fitting (I have a Large shirt and I'm 6'0' and 200 lbs). Very comfortable moving and working with it on. I would definitely get this shirt again.
Age:55–64
Weight:175–200 lbs.
Height:6'0"
Yes , I recommend this product
jwaters
NV
Nice and warm but not durable
6 months ago
Warm? Yes Smell free? Yes Durable? No Took this to the Arctic and it kept me incredibly warm while out in near 0F temperatures. Upon getting back home though, all it took was 1 wash to create almost a half dozen holes in the fabric. The shirt was washed per instructions in cold water with woolite on a delicate cycle, removed promptly and when hanging to air dry the holes were visible. While not the most expensive, it still sucks that this has almost become almost a one and done top. I can only imagine that it will only last a couple more washes before it is unusable.
Age:25–34
Weight:175–200 lbs.
Height:6'0"
No, I do not recommend this product
Brien
Upstate NY
very nice
8 months ago
I bought this as a long sleeve tee but it's form fitting on me. I'm not complaining. I wore it as a base layer under a lambs wool sweater and it was perfect. It's soft enough and not itchy. This is how Merino should be. However, I washed it in Outback wool wash before wearing. That seemed to make it softer. The sleeves are just long enough which is an improvement over my experience with other brands. Fabric weight: I'd call it medium weight. I have several Merino pieces. My Smartwool tees, for example, are very thin. My Woolx quarter zip is thick. This is inbetween. Negative (or a suggestion): I would like to know that REI clothing is made with non-mulesed wool. I'm not an animal rights person but mulesing is horribly cruel to lambs. Where does REI stand on this issue?
Yes , I recommend this product
Sleepy Bear
Received free product
Michigan
Warm, soft, breathable, wonderful
6 months ago
I recieved this item as a member of REI Trailblazers to review. This shirt is fantastic for cold-weather activity. Merino wool has almost magical qualities that become apparent once one gets warmed up. Put this to work immediately as a base layer at our farm on a +15F morning. It fits tight to your body. At rest before work this shirt does not cause overheating under thicker outerwear. It's soft (and gets softer with each wash) and comfy. Then once one warms up it retains your heat efficiently. If you start sweating this shirt becomes quite breathable and does not lose its insulative properties, keeping you warm even while damp. This becomes important once one stops working - unlike other fabics one doesn't feel chilled from sweaty dampness. A wonderful piece, highly recommended.
Age:65–74
Weight:275–300 lbs.
Height:Taller than 6' 5"
Yes , I recommend this product
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