Merino (my wooly fiber of choice, as you may know by now) gets shoehorned over into the cold weather clothing cubby, and really, it makes sense. Stylish sweaters, soft long underwear and hoodies, it’s the kind of stuff that makes up good winter base and mid-layers. But Smartwool makes what they call a “microweight” layer, too, and believe it or not, it works well in hot weather, too. I know — I wore this stuff for a long sweaty day in 94F weather.

First, I really like the material. It’s soft, and no, for the 1000th time, it’s not itchy even though it is, indeed, wool. Smartwool’s “intimates” line is made of their 150 weight merino, which simply means it’s their finest, lightest fiber. It launders up nicely, getting softer each time I put them in the wash and while I prefer not to dry my woolens, the underwear made it through the dryer without shrinking.

Next up, the fit. Smartwool’s clothing seems true to size, meaning they fit exactly as I expect they would. The underwear stays put, no awkward climbing (a-hem). The adjustable straps on the camisole don’t slip. It’s all really comfortable, no itchy plastic-y stitching next to your skin, no bunchy seams, no weird lines wrecking your svelte (okay, or not so svelte if you’re me) profile.

As for wearing super light wool in next to the skin on a 94F day? I’m sold! Sure, things got a bit sweaty. But the clothing didn’t stick to my skin, develop that weird sweat plus artificial ingredients smell, and it dried quickly.

I tried the camisole and the underwear but Smartwool’s microweight line comes in a bunch of cuts and colors, for both men and women. As usual, Smartwool’s products aren’t cheap — the camisole is $45 and the boyshort/hipster underwear are $40. If you’re used to buying expensive underwear, this won’t surprise you, but it is a pretty steep price for a person who’s used to paying department store prices on three packs of boyshorts from Hanes. (And now you know more about my underwear than you ever needed to know. Apologies.).

That said, if you don’t mind paying the price, I can tell you that I have Smartwool in my travel and outdoors wardrobe that’s easily 15 years old and still performs very well. It’s tough stuff, it feels great next to your skin, and it lasts. That makes for great travel gear, even in the blazing heat.

Want your own microweight Smartwool underwear? Sometimes, you can find it for a bit less than Smartwool’s full retail price on Amazon.

Need more merino wool? We’ve reviewed a whole variety of stuff. Start here.