Baselayer Options for Adults (And How They Keep you Warm!)

Swimming through the many options out there for base layers can be pretty tough.  Between Synthetics, Wool, Silk and all the different brands, there are plenty of choices to make.  A lot depends on what you will be doing when you wear them, how much you want to spend and how cold (or hot) your body tends to run (because, truly, everyone is different.)  Over the past few months, we have been putting a bunch of different ones to the test here (with the exception of anything silk).  We literally have a tendency to wear base layers daily and have been rotating them through different conditions to see how they perform.  This post is our best shot at making all those choices a little more clear….all in one spot!  As always, please feel free to post your questions in the comments section (or on our Facebook page) and we will make sure to answer them as soon as we can!


Wool (Merino Wool, to be specific) – Our go-to choice for colder temperatures, year-round comfort (because the wool both helps warm and cool).  For winter adventures, wool tends to feel warmer right next to your skin and you can get away with less bulky mid layers (usually.)  The downsides?  It seems to not hold its shape quite as well while wearing and it is usually recommended to NOT be thrown in the dryer.  Expect to pay higher prices for Merino Wool.  It’s the nature of the product.  Rest assured you ARE paying for quality, and go ahead and invest in one quality set.  They don’t stink and you can wear them again and again without washing!

Icebreaker:  Check out the review we posted last winter of both their adult line AND kids’ line.  They are a favorite for sure (and one of the only places I have found little kids’ merino wool base layers.)  Icebreaker has a bunch of new colors for the season too (including some fun stripes, camo and brights.)

I/O MerinoThis Australian Merino Wool company is definitely up and coming in the U.S.  (As a sidenote, you can find them on Instagram (@iomerino) – they show some awesome shots!)  I had a chance to review a pair of their tops (Long Sleeve Zip) and bottoms (Tight 200) and love them.  They are lightweight and warm (per the nature of merino wool), fit great, and hold up through an abundance of tests and washes.  In reality, they are very similar to the Icebreaker line (just a tiny bit cheaper.)  They don’t itch, can be used as both a base layer and sleepwear and perform beautifully all year long.  I love the thumb holes to ease layering with the thin Long Sleeve Zip – they’ve definitely covered the details!  I wore them as an extra light layer at the end of the summer, under vests this fall and now as my base layers for skiing, snowshoeing and winter running.  I wash them after about 8-10 uses and, despite the fact that they are not recommended to be thrown in the dryer, they have held up wonderfully.  In fact, I have seen no shrinkage (which I can’t say about Icebreaker.)  Two thumbs up!  **I/O also has a full line of Merino Wool pieces, including vests, jackets, bras and underwear.**

W Full Tight 200 longsleevezip


Polyester – Tends to be a little cheaper (though not “cheap” by any standard) than Merino Wool, a little less warm to the skin, but performs very well.  I grew up wearing polyester from Patagonia, and still put it on my children (Patagonia makes baby long underwear for even tiny infants – starting at 3 months.)  In general, polyester tends to stink when you sweat in it, though technology is changing and this isn’t quite as much of an issue as it was before (see Terramar below.)

Terramar:  I cannot say enough good about the Hottotties TXO 2.0 line.  It is uber warm, very soft to the touch, has the right amount of stretch for a great fit every time and does NOT stink.  At all.  I have literally worn my women’s scoop for 10+ consecuative long, sweaty runs and have had no need to wash it.  It has a carbon-based yarn that actually reflects heat back in (unique to the TXO line) and boasts a UPF of 50+.  Even better?  It’s substantially more affordable than Merino Wool ($50 for the shirt), as an example.


While we have yet to review the men’s line from Terramar, we are confident they are comparable to the women’s line.  **And we’ll be sure to let you know as soon as we get a chance! Terramar also has a kids’ line with sizing as small as 2T.  Again, we’ll let you know about that ASAP!**

Columbia also has a lighter set of base layers using their Omni-Heat technology that we reviewed last winter.  It’s a great lightweight layer if you are moving, but honestly doesn’t do any good if you are standing still (and is cool/cold to the touch.)

ColfPRUF is the most affordable option we have found as far as base layers.  They run around $20 for a top or bottom and do fairly well as far as keeping us warm.  ColdPRUF has 9 different “levels” of base layers and we reviewed the Eco-Terra or Pro-Tek line.  They say it is for “when the forecast is the furthest thing from your mind”.  While Mtn Papa has been more favorable towards them (again, every body really is different) they perform well under moderate to cold temperatures.  They are not what I reach for when it is sub-zero, but I can count on them for temperatures in the 20s.  While I will stand by my statement that you get what you pay for in base layers, if money is tight, these are a great option.  They are very soft, layer well under clothing and have held up to many wears and washes well.  Again, thanks to ColdPRUF’s odor control technology, they don’t stink after a great brisk run, ski or snowshoe.

ecc pro-tek womens eco pro-tek mens





Other options include silk and fleece base layers.  Silk tends to be what you would wear under your normal clothing for a little extra warmth or for more mild conditions and fleece tends to be for when you need to stay uber warm (or used as a mid layer.)


Terramar, ColdPRUF, and I/O Merino generously provided us this gear in order to facilitate this review.  However, as always, the opinions expressed here are completely and honestly our own.  Additionally, a few of these  links are affiliates.  Thank you so much for clicking through them to make your purchases – it helps offset the cost of this blog in a (VERY VERY) small way!  You can find my full disclosure here.  These pictures were taken from their respective sites. 


© 2013, Tales of a Mountain Mama. All rights reserved. Republication, in part or entirety, requires a link back to this original post and permission from the author.


  • Amelia lives with her husband and five young children outside of Jackson, WY in Grand Teton National Park. As a mom, she quickly learned that the secret to sanity was to spend more time outside where tantrums don't see quite so bad. Amelia started TMM in 2012 to help encourage all families (including her own) to get outside, no matter the weather. Due to the necessity of having to keep so many kids warm and happy, she has become an expert in kids' gear and loves being able to share it with others.

7 thoughts on “Baselayer Options for Adults (And How They Keep you Warm!)”

  1. I had a Geo Fleece quarter zip from Terramar that I LOVED (especially the price!) but they cut that, and my favorite base layer top, off when I hurt my shoulder… ack! Shopping for new stuff is fun though, minus the actual spending money part. I am thinking of getting a midweight Smartwool top– have you had any experience with Smartwool and the itch factor? I like the weight of it, but don’t want something that will be itchy at all. Thoughts? (P.S. I’ve got some Patagonia merino baselayer bottoms and while they are soft and light for the warmth factor, they are getting thin and out of shape fast… bummer)!

    • Mtn Papa has some Smartwool that he does like (and hasn’t had an issue with the itch.) The quality of it doesn’t compare with other wool brands we HAVE tried, though – it just doesn’t hold up like the others seem to. But, other than his one pair, most of our experience with Smartwool has been the socks (which just get holes in them WAY too fast…in our opinion!) Hope that helps!!


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