I have been wearing wool base layers for over 40 years - far better than synthetic unless you need to go light and can wash often. The Smartwool 250 from before 2012 was the BEST. Like so many other name brand companies, in an attempt to maximize profits and increase purchases, the product lines are ever0changing. You guys should learn when you produce a great product, leave it alone. The newer version 250 base layers (also the zip model) are over-sized. The Medium fits like earlier model Large, and there is too much fabric. The change was for the worst. Pity.

I'm 6'2 230 in excellent condition, athlete, balanced, arms nice and long. The shirt fits surprisingly big, which is an ok thing since I don't love tight clothes, even baselayers. I love most of the shirt, but the sleeves are approximately five inches too long. Fits like some expensive designer stuff I have that's meant to have extra long sleeves, those things I rarely wear because of it. I like freedom with all movement, no matter how small. Bunched up sleeves cause problems, can be dangerous depending on what you're doing, Might have them altered but the shirt shouldn't require it. Probably send it back. Weird how fits change from season to season. Cold out here in the Oregon Coast Range. Needed this thing to work, and needed it now. Frustrating.

This is still a great product. However, I have 4 that are older and finally wore one out and just replaced it. The fabric is still great on the new one but the fit is off. I would say the shirt is now slightly over-sized and maybe a hot washing will shrink the fit. This is why I held back one star on the rating. The label/tag on the lower left inside seam rubs against my skin and I have a callus there now (I wear these a lot).

These are the best base layering undershirts I have ever purchased or used. Plain and simple, the very best. I purchased the NTS250 and it performs well in my home state of Colorado. The wicking capabilities of Merino Wool is outstanding. I have never had an issue with this fabric not performing to it's high standards. I am six feet, four inches tall and weigh 200 pounds. I have a 38 inch waist. Size XXL or 2XL fits me perfectly as I like a somewhat loose fit. Likewise for the SmartWool NTS150 short sleeves - they too are the best for warm weather and it's cooling capabilities. A little pricey, but it's the best.

Bought a black midweight 250 before a college football game, very soft material with nice stretch. Usually wear XL (6'3" 225#) but bought an XXL thinking an XL would be too tight, in hindsight I would have went with the XL as this tends to run true to size. Its an athletic fit and I didn't want something super tight but there is a lot of give in the fabric. Great base layer though, very very soft, well made and WARM! Does a great job wicking and keeping you warm in a variety of temperatures. My only concern (and its very minor) is how it will hold up over time. 2 washes in and no problems so far, no pilling as I have seen reported in other reviews. Recommend washing warm wash inside out and dry on a rack. No need to separate from other clothes. All in all a great buy and will buy more of these, 5/5 stars and I'd go higher if I could. Love the shirt!!

I bought this crew 250 base layer to primarily wear on a March snowboarding trip to Vail, but also to serve on early summer hiking trips, as well as to wear around the house on cold days.

The base layer worked well across a wide range of temps while I was at Vail. On +5°F cold temps paired with a mid layer zip up and snowboarding jacket and +55°F warm temps paired with a light softshell, this base layer performed spectacularly. Breathed well, managed sweat well on heavy output runs, and left a 5 day trip (worn every day) completely stink free.

Another big plus is that it looks acceptable enough on surprise video calls (you know, when your boss randomly says "Hey can you chat real quick?" and you have to follow-suit and turn on your camera?...) during WFH. Can't wait to put it through it's paces further on the trail and mountains this spring and fall.

The only slight complaint that I have it is just slightly oversized in the sleeves and general fit (for a base layer). Not too big of a deal, but the wool fabric gets stretched out a little bit after the first wear too, however I have read that it bounces back after the rare wash.

I bought one to use when I'm outdoors on the weekends. I was so happy with it I bought more to wear to work. At work I wear a uniform and have to present a highly professional appearance. These shirts are great because they're extremely comfortable and warm while not adding bulk. I'm 6' tall and weigh 220lbs with a 35" sleeve and the XL fits me very well.

Great fit and appears to be be quality craftsmanship. I will be testing in Iceland in early April, so performance has yet to be fully evaluated.

Love the thermal layers, they're so comfortable. #sweepstakes

Great for mildly cold weather. Breathes well.