Cotton Kills! Or: Why You Should Be Wearing Merino Wool Hiking


What’s all the fuss about merino wool?

If you are somewhat interested in the outdoors adventure world you have probably heard about merino wool hiking apparel.

And I’m pretty sure you wondered if you should buy some or maybe if it’s just some kind of overblown sales pitch to make you spend more.

Because let’s be honest – high-quality merino wool clothing is not cheap. So why not stay by your good, old cotton tee?

Why you should never wear cotton when hiking

Unless you are going for a pleasant stroll in your city’s suburban park, you should wear only technical hiking apparel.

Cotton is cheap and really comfortable to wear, I agree.



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But it also takes too long to dry. It might not be a problem during a short trek on Sunday, but it can become dangerous when on a longer hike. Sweaty cotton shirt right to your skin behaves like a wet, cold compress.

It provides no insulation because all the air pockets fill up with your sweat. Cotton fabric does not have the ability to wick away moisture like the technical synthetic or merino wool do.

The moment you stop walking or climbing, your body cools down very fast, with all that water plastered on you – you are in danger of hypothermia.

And I hope you never have such a silly idea as hiking jeans, right? They weight as much as my week's food allowance and once wet (it rains sometimes) they never dry (I exaggerate only slightly). 

Do you know about all the amazing qualities of merino wool clothing? Read to find out why you need to wear merino when hiking!

Cotton and her evil sisters

Cotton is not the only fabric you should avoid when hiking.

All cotton blends (like cotton-polyester) or fabrics named corduroy, denim or flannel are cotton-based. In addition to that, all cellulose-made fabrics also absorb water very fast and don’t insulate when wet.

Stay away from clothing made of viscose, Tencel, Modal, rayon or lyocell. Even bamboo is not advisable – its benefits are more of a sales pitch than reality.

On the list of fabrics to avoid is also silk – highly absorbent fabric losing its insulating abilities when wet.

Wool or synthetic

Now that’s a good question. I remember how my Mom hated polyester shirts because of how they didn’t breathe and made you stink.

I internalized this message very well and stayed away from anything synthetic throughout my life. But then I started hiking again and realized that modern technical synthetic apparel is not exactly the polyester shirt from the ‘80s.

Do you know about all the amazing qualities of merino wool clothing? Read to find out why you need to wear merino when hiking!

I see the choice between synthetic and wool as a personal one. I have shirts made of both fabrics and I like them. It is said that synthetic stink up faster, but many producers add special woo to slow bacteria from growing.

Synthetic materials are better at wicking moisture away from the body and usually dry faster. On the other hand, wool fabric is highly insulating even when wet – it absorbs up to 35% in its dry weight in moisture vapor but still feels dry.

That’s why you don’t feel sweaty and clammy when wearing merino base layer. In contrast – synthetic fabrics feel wet after they absorb about 7% of moisture.

My personal choice? Merino wool is always great, especially in warm and cold weather. The synthetic base layer is my preferred choice for a really hot weather when I don't care to feel a bit sweaty and the cooling effect of the wind on wet might be even pleasant. Some of the synthetic fabrics are so delicate and soft, they feel really nice on the skin.

But really - both kinds of fabrics are fantastic. 

So what’s the magic with merino wool? Why is it special?

Do you know about all the amazing qualities of merino wool clothing? Read to find out why you need to wear merino when hiking!

Merino sheep is a very old breed of sheep living in the mountains of New Zealand, Australia, South Africa, Italy, and Turkey.

They evolved in a climate that required thick insulating coat to survive harsh freezing temperatures but also light enough so they wouldn’t overheat in the mid-day heat.

Here's a short list of amazing qualities of merino wool:

  • Merino wool has an amazing ability to transport moisture vapor away from your heat zone right next to your skin. Thanks to this you stay dry and comfortable.

  • This you already knew: merino wool hiking clothes are great at keeping you warm. Wool fibers are able to trap air better than any other fabrics. All that trapped air is the perfect insulator. What’s crucial, wool keeps the warming and insulating abilities even when wet.

  • What you might not have known already: merino wool hiking clothes are also awesome at cooling. What? Didn't I just write that it’s best for keeping you warm?! But just think of the sheep – they can survive very hot summer days with all that wool. How can that happen?
    All that moisture that wool is able to store is cooling the air right next to your skin when it evaporates. When your body heats up and you sweat – all that moisture evaporates through the wool fibers and your body is cooling. A thin merino base layer is perfect for a hot summer hike.

  • Sometimes we perspire too fast for the moisture to evaporate fast enough and the fabric needs to wick it outside. Both synthetic and merino clothing do that, but merino wool is able to wick away moisture when it is still in its vapor state.

  • Thanks to the wool’s ability to move away moisture it does not create a bacteria-friendly environment. Merino apparel is famous for being stink-free even after being worn for a long time in really sweaty conditions.
    More than once I have worn my merino base layer or socks for two or three days without stinking or feeling disgusting. Now that’s something in the wild!

  • Merino wool is static-resistant which means it doesn’t cling to you in an annoying way or causes sparking.

  • It is also fire-resistant and flame-retardant making it a good choice around campfires. It does not melt or stick to your skin – so much safer than other fabrics.

  • I still remember with some horror how my father used to wear lambs wool sweater directly on his skin. As a kid, I hated woolen sweaters, scarfs or hats because of the itchy and scratchy fun.
    But merino? Not your typical wool.
    Merino fabrics are actually pretty soft. It is also unusually, for a wool fiber, stretchy. Thanks to it merino garments are comfortable and return to their shape after being stretched.

Do you know about all the amazing qualities of merino wool clothing? Read to find out why you need to wear merino when hiking!
  • It is generally claimed that merino wool is hypoallergenic. My skin is sensitive and I have multiple allergies. When I was wearing merino base layer for the first time I noticed itching and even swelling in areas under pressure: where the backpack’s belt was pressing hard the garment against my skin.
    For the next few days, I was wearing synthetics and staffing the synthetic top fabric under my merino undies where the belt went…
    After a few days, I put merino again and nothing like that happened again. So I am aware that there might be some irritation with the seriously sensitive where there is hard rubbing against the skin.

  • Merino wool garments have better UV-protecting properties than other fabrics.

  • Merino wool is of course completely natural: made by sheep, renewable and biodegradable. Every year merino sheep produce a new fleece for us to enjoy.

  • The above-mentioned softness and elasticity mean merino garments are less prone to wrinkles. What is even better? You can wash it in a machine!

Do you know about all the amazing qualities of merino wool clothing? Read to find out why you need to wear merino when hiking!


I’m pretty sure I convinced you to get interested in merino products. So where should you begin?

What kind of merino products should you get?

Now that you want to throw all your retirement savings on all things merino, it is worth deciding where merino is the most beneficial.

Merino base layers.

That's where merino wool products really shine. I absolutely love my short- and long-sleeved base layers made of thin merino wool.

For colder temperatures, you can get a thicker base layer and also leggings. I highly recommend them as your camping pajamas.

Check out some examples by reputable and recommended producers:

Can’t see anything? Try refreshing the page.

Do you know about all the amazing qualities of merino wool clothing? Read to find out why you need to wear merino when hiking!

Merino underwear.

This one is the most surprising – who would have thought wearing woolen undies could be so comfortable?

I have a few pairs of merino undies and can’t recommend them highly enough. No matter how much I’m sweating, I don’t feel I hike in wet underwear.

Their odor-repelling abilities are particularly welcomed here, as well. I admit to wearing the same pair of undies for two or three days when there was no other choice and I didn’t feel stinky or dirty.


Absolutely amazing.

In addition to the undies, I also own a merino bra - very comfortable, although not as elastic (holding) as a synthetic one.

Still - I like hiking with it. 

Below you can see a few great examples of merino underwear:

Can’t see anything? Try refreshing the page.

Merino Socks.

Contrary to the other kinds of garments, you probably won’t find a 100% merino socks.

They generally are made of wool blends with high merino makeup. Thanks to mixing it with other fibers, they become more durable.

Do you know about all the amazing qualities of merino wool clothing? Read to find out why you need to wear merino when hiking!

There is a huge variety of merino socks to choose from for every kind of activity or season.

I don't wear merino socks directly on my feet, but rather over a thin Coolmax liner. This system works perfectly for hiking in boots with a heavy backpack.

I don't think there is any serious hiker out there who does not wear merino socks. There is just no excuse to use cotton here! Mixed-wool socks are absolutely superior to provide the perfect environment for your feet when you hike, run, walk or trek.

You can pick whatever thickness and cushioning you need for the right season, shoes/boots or type of hiking you do. 

Mid- and outer-layer.

Merino wool is the perfect fiber for layering. Its superior insulating properties make it a great choice for sweaters, soft-shells, and jackets.


BUT. Heavyweight wool dries very long - so if you sweat a lot or can get wet, better stick to a good fleece or primaloft jacket.

To be honest, most of those are also way beyond my budget but must be pretty awesome to have. I can only image how comfy they are to snuggle to in front of a fire at a winter cabin :)

Merino buffs, hats, and gloves.

I have two merino buffs and I absolutely love them. I wear it not just during my hikes – often as a hat, but also whole winter in the city. For me, it’s a must. I am thinking also about getting a merino hat in addition to the buffs to create an unending list of combinations for every possible weather condition :)

Merino gloves can also be a fantastic idea - even when they get wet, they still provide protection. If you hike with cold winds as your company, wearing gloves can save your hands. If you expect rain, you can have a thin waterproof mittens to wear over the merino liners.

Check below a whole rainbow of colors, styles, and shapes in the accessories department:

Do you know about all the amazing qualities of merino wool clothing? Read to find out why you need to wear merino when hiking!


What are your experiences with merino wool hiking apparel? It's awesome, isn't it? :D

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