How to Choose Base Layers
REI Co-op Midweight Long Underwear Crewneck Shirt - Men's
This product is not available. Good news: we have a newer version.
Excellent flexibility and moisture control make the men's REI Midweight Long Underwear Crewneck Shirt an outstanding choice for a wide range of activities in cool conditions.
Shop newer version- 4-way-stretch polyester fabric wicks moisture off skin and dries fast to prevent you from feeling chilled or clammy; brushed inner surface feels soft and warm
- The fabric also has a UPF 50+ sun protection rating
- Space-dye process produces a textured color that's unique to each garment
- Nonchafing flatseam construction and shoulder-seam placement increase comfort under pack straps
- Extended length helps the shirt stay tucked in; smooth outer surface slides easily under other layers
- The men's REI Midweight Long Underwear Crewneck Shirt has a next-to-skin fit that hugs the body for optimum performance
- 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
| Best Use | Hiking Snowsports |
|---|---|
| Shirt Type | T-shirt |
| Fabric | Polyester |
| Sun-Protective Fabric | Yes |
| UPF Rating | 50 |
| Moisture Wicking | Yes |
| Quick Drying | Yes |
| Underwear Weight | Midweight |
| Sleeve Length | Long Sleeve |
| Gender | Men's |
| Sustainability | 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.
Buying Advice
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Better gear is built together
From feedback to field testing, all of our gear is dialed-in by REI Co-op members. Their adventures informed every stitch and detail—making for better, longer-lasting gear.
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theJBRU
Minneapolis, MN, United States
Excellent shirts
10 years ago
I love this shirt. I own three of the current style and one that has the same construction and fit, but made of a different material. They provide a good amount of warmth and also wick well. For me, the ultimate selling point is the way the fabric is constructed. The interior is slightly fuzzy, giving the shirt the warmth and wicking you want. The exterior is smooth and a little slick. This allows the shirt to slide easily into outer layers if you're wearing them and has the side benefit of not allowing pet hair to stick to it. The only issue I've encountered with the shirts is from my cat using me as a climbing post. Her claws have snagged threads on a couple of the shirts, but trimming those threads returned the shirt to typical performance with only minor cosmetic damage. Overall, I highly recommend these shirts
Yes , I recommend this product
Girion
Orange County, CA
Great base layers
10 years ago
I purchased the lightweight and midweight long sleeve base layers in advance of a long weekend backpacking trip to Santa Rosa Island. Was looking for something to keep the sun off during the day hikes and keep me warm during the cool windy nights (temps ranged between 75 during the day to low 50s at night) these were the real deal. I was originally looking at the Capilene base layers but wasn't thrilled with the fit. The rep at REI suggested these, so I tried a few sizes on. For me (6 foot, 175lbs) the large was the perfect fit. Its fitted, so not too loose and not too snug. They wore well under a day pack, and dried fast after between 7-14 miles on the trails. The midweight was great under a fleece in the evenings and I used it as my sleeping layer as well and was comfortable all night long. Got the blue and titanium and now wear them around the house and out in the mild SoCal evenings. Good product and value.
Yes , I recommend this product
Travis P.
Colorado
Lightweight, soft, and warm
9 years ago
I love this shirt. I wear it under my down jacket when rock climbing and it is perfect. The shirt itself is warm enough to wear on its own during the winter so long as the sun is shining. It's incredibly soft on the inside and has a great feel on the outside. A great base layer
philz
hermosa beach, ca
Underwear Shirt To Add Layers
9 years ago
This is a great underwear layer shirt for being active. The fit and material is very comfortable and you can add or take away layers using this as a base.
H20
California
So warm!
1 year ago
This is my very favorite long underwear! I use it when backpacking and car camping! So warm! It's the best long underwear that I've ever owned!
Age:45–54
Yes , I recommend this product
mountainwalker
Long Island, New York
Great underlayer or leisure top
9 years ago
EXCELLENT EXCELLENT EXCELLENT!! Good fit, comfortable, warm. Highly recommended.