Customer Reviews Smartwool Merino 250 Base Layer Crew

Got this great shirt in the beautiful Nival Blue for my husband, who only recently began to appreciate the many benefits of merino wool. Now that he's hooked, we're glad I found this one! It's soft, temperature regulating, high quality, and flattering, as well as being versatile and smell resistant. YAY!

Smartwool thermals aren't just another base layerthey're the benchmark I now measure all cold-weather clothing against. From the moment you slip them on, it's clear these aren't ordinary thermals. The Merino wool is incredibly soft (zero itch), remarkably breathable, and almost magically able to regulate temperature. Whether I'm skiing, hiking in sub-freezing wind, or just walking the dog on frosty mornings, they keep me perfectly warm without ever overheating. What truly sets Smartwool apart is the balance of comfort, performance, and durability. The fabric stretches naturally with movement, never bunches, and holds its shape even after repeated washes. Odor resistance is another game-changerI've worn them for multiple long days on a winter road trip, and they still felt (and smelled) fresh. The fit is athletic but forgiving: snug enough to trap heat, yet flexible enough for layering or high-output activities. Seams are thoughtfully placed to avoid rubbing, and the overall feel is light, almost like a second skin. Yes, Smartwool thermals are an investment, but they outperform cheaper synthetics by a mile. They last longer, feel better, and make cold-weather adventures far more enjoyable. If you're serious about staying warm and comfortable, these are absolutely worth every penny. Bottom line: Exceptional warmth. Exceptional comfort. Exceptional quality. Smartwool didn't just make a thermalthey perfected it.

I haven't had a proper pair of thermal base layers in 15+ years... I'm so glad my partner turned me onto Smartwool because this top is amazing... and fits perfectly! (I'm thin and 6' and the "S" fits me perfectly.) Totally endorse this piece of kit!

I haven't had a proper pair of thermal base layers in 15+ years... I'm so glad my partner turned me onto Smartwool because these bottoms are amazing... and fit perfectly! (I'm thin and 6' and the "S" fits me perfectly.) Totally endorse this piece of kit!

This can be used as both a base layer and as a shirt! Love it!

An old man who still runs trails year-round. I absolutely love the Classic Thermal's cut (fit), too!

This is a great layering piece and is great on it's own. My husband owns it in several colors.

This shirt saved my last trip to New York! The base layer is stylish enough that can be used as the main shirt and it protects you really well from the elements! It's also great to use while inside an airplane. Not too hot, not cold at all just right!

Enjoy wearing the base layer all day long and didn't even need to take it off.

Use my smartwool baselayer hunting and ice fishing in Mainelove 'em! Wouldn't buy anything else

I've used this for cycling and it performs well. It's warm, yet breathable. Note that the body length of the shirt is on the longer side.

Office is cold, I wear my thermal under dress shirts for a more comfortable day.

This was given to me as a gift and I love it. Can be work casual or dress it up

Everyday use

love it other than the label on the inside. sewn in and hard to remove.

I love this base layer, I wear it every morning on the cool days on walks with my dogs and it keeps me so warm and cozy. I will be buying more Smartwool product in the suture after this purchase!

I teach yoga in outdoor environments and this shirt allows me to breath, stay warm and dry. Perfect!

A fantastic daily shirt that can be used for all types of weather.

I wear long underwear half of the year living in the mountains of Idaho. This top is my favorite as a base layer. It is warm, doesn't collect moisture and very comfortable. Highly recommend.

For light hiking these are supremely versatile. Perfect for the Shikoku pilgrimage. Two shirts, one pair tights, one beenie, three pairs socks- all merino wool. Combined with water and windproof layers I was comfortable in late winter/early spring conditions, 40 to 65 degrees for the seven weeks I walked with a 30L backpack. I am thoroughly pleased with the performance, styling and construction of Smartwool garments.

Layer for back country skiing.

My friend looks great in it, loves the color!

The perfect lightweight thermal when you want warmth, comfort and layering that allows normal movement.

The best base layer I have ever used. This is my first time using Merino wool as a base layer and I am a believer. I hunt in freezing temperatures and never once was my core cold. I will be buying more Merino products!

My 14-year-old son had been wearing Smartwool baselayers to mountain skiing for many years, but last year we couldn't find the right kids' size for him. I even emailed the company to ask if they would make an XS size for slim teenagers. Fortunately, this year he tried the S size and it fits him well. He is 5'5.