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  • Itch-free merino wool wicks moisture, naturally resists odor and retains warmth in cold weather
  • 8 in. front zipper ventilates on demand; raised collar keeps your neck warm in the cold
  • With a UPF 50+ rating, fabric provides excellent protection against harmful ultraviolet rays
  • Shoulder panels eliminate top shoulder seams, reduce chafing and optimize comfort under pack straps
  • Flatlock stitching eliminates abrasion, increases comfort and enhances fit by reducing bulky seams


View all Smartwool Men's Long Underwear Tops

REI membership


Best Use Multisport
Shirt Style Zip-front
Fabric Merino wool
Sun-Protective Fabric Yes
UPF Rating 50
Moisture Wicking Yes
Underwear Weight Midweight
Sleeve Length Long Sleeve
Gender Men's

Size chart

Rated 5 out of 5 by from My first baselayer This was my first base layer I had ever purchased. I've just spent too many nights shivering around a campfire wishing I had brought a few more layers. This really does the trick! It is incredibly warm yet breathable, meaning no excessive sweating. I usually wear a medium and my SmartWool is true to size. It really holds in heat, so it's best used on cold days. I got too warm in mine on a day hike in about 60 degrees, but I've enjoyed it so much I bought a Microweight Zip-T for those warm days that I'll be exerting myself. I plan on swapping them at night so I have a nice, warm, and dry Midweight for nights by the fire.
Date published: 2012-12-27
Rated 5 out of 5 by from The Benchmark for Merino Wool Base Layer Garments None better. I have several of these Smart Wool NTS 250 shirts. I wear them for work, snow removal, hiking, fishing and any other cold weather outdoor activity. They wick sweat/moisture very quickly and there's no stink afterwards. These shirts dry fast and you don't get that cold, clammy feeling like with other fabrics. Additionally, I wear them inside my home and turn down the furnace for energy savings during the colder months. For size comparison, I am six feet four inches tall, 40 inch waist and weigh 210 pounds. I wear a 37 inch sleeve shirt. Size XXL fits me perfectly. They are pricey, however if you want a quality made, warm, next to the skin base layer, this Smart Wool shirt is for you.
Date published: 2016-08-26
Rated 5 out of 5 by from My new favorite shirt When I'm not backpacking, I'm traveling. This shirt is great, because it breathes and helps to regulate body temperature in changing conditions. I'm 5'10" and 150 lbs. The large fits in the shoulders and chest, but is baggy and long in the waist and the sleeves are a tad long. But I use this as a shirt over a thinner SmartWool T-shirt, and it's a perfect combo for hiking, hanging around the house, or flying across country.
Date published: 2013-01-27
Rated 5 out of 5 by from Perfect comfort and warmth Spending this winter working outside in upper BC and Alberta. Smart wool from head to toe has been the key in staying warm while being less bulky. A whole set fits easy rolled up in a pack. You can hand wash a set after days of use and move into the 2nd set while drying. A must for any long period of cold weather exposure.
Date published: 2013-12-10
Rated 5 out of 5 by from Way less odor than synthetic shirts I own base layers from REI, North Face, Nike, Brooks, etc plus numerous technical jerseys from races I have competed in over the years from a host of manufactures. They all share the common trait that after the slightest amount of perspiration, wait 2 hours and you smell like a locker room. The natural wool product is head and shoulders above the synthetic material in this regard. During cold weather backpacking trips it would get moist but it would take it 3 days to get as bad as a synthetic does after 3 hours. I like that the shoulders are a separate piece of material so there is no seam at the top of the shoulder. This prevents a raw spot from the shoulder straps of a backpack. The material is soft to the skin, no itching, chaffing, etc. Fit is true to size and warmth is as good or better than a synthetic in my opinion. I have recently decided this will be going with me to Rainier this fall instead of the synthetic one I had originally planned to take. 5 days in it without taking it off will certainly push the limits of its ability to fight odor, dry quickly and keep me warm.
Date published: 2013-01-17
Rated 4 out of 5 by from Excellent Baselayer Top Piece This is a great piece. The front zipper allows one to control temperature. The high collar neckline keeps drafts out. I've worn this at 14,000 ft in January with -15 windchill and also during winter skills excercizes. This piece breathes well during periods of high excertion, is warm on the mountain, and yet confortable on the drive home. Love it!
Date published: 2014-01-25
Rated 5 out of 5 by from worth every penny This sweater is great as a base layer, it is very breathable and dosn't retain ordor like cheaper cotton fabric. I work outside in the cold a lot and this has become my go-to base layer for staying warm. When the temperature rises or I move inside, it's easy to take off and packs very small.
Date published: 2014-01-25
Rated 5 out of 5 by from My favorite long sleeve shirt ever I originally bought this over 4 years ago and it has become my favorite shirt ever! I love the feel, the fit, how comfy it is, it's warm, it wicks sweat away and doesn't smell, it doesn't itch, it looks great, the zipper makes it easy to regulate your temperature, and it's an all around outstanding shirt. I wear this shirt ALL THE TIME, around home, out hiking, walking around town, and so on. It's what got me hooked onto smartwool. This is easily my favorite smartwool product I've had yet. The very first shirt I bought years ago eventually had a zipper failure. The little metal handle part you grab broke off, but REI swapped the shirt out for a brand new replacement one because they're awesome like that. Since then it's worn well. The elbows have both developed holes from being worn so much. When I found those, I went to REI and was thrilled beyond belief when I found that they still carry this shirt. I couldn't find it searching on the website and was so happy when the REI girl helping me found it that I gave her a big huge hug. It looks like the new version of this shirt is almost identical. The one thing they changed is the improved the zipper. How 'bout that. ;) My old one is a shiny silver zipper handle. The new one is a stronger black one which is great news. I'm utterly stoked to be getting another one of these, and I think I'm gonna have to order yet another one just in case REI stops carrying this shirt. It's just that good. Also, quick note, if you pull the sleeves up past your elbows, that may stretch the elastic in the wrists. It will go back to a certain degree over time, but I don't think it goes fully back if you keep the sleeves up a lot. It's best not to stretch that too much. Other than that, if you're looking to get this shirt, I can whole heartedly recommend that you GET IT! Just pick out the size and color you want, or even get a few so you've got some color options (I've got the green one) and you'll be a very happy camper. It's one of those shirts that makes you glad you bought it every time. Thank goodness it doesn't stink... because I reach for it often. It handles repeated washes well too. ;) Yeah. This shirt gets my highest recommendation.
Date published: 2014-10-20
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Is it okay to machine wash the smartwool?

Asked by: Weiyan
This top can be machine washed in cold water and tumble dried on low heat. Full washing instructions can be found on the inside tag of the top.
Answered by: REIservice
Date published: 2017-04-27
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