Explorer Mikael Strandberg

Extreme cold; How to dress and what thermal underwear is best, wool or high tech yarns?

As soon as extreme temperatures and wild weather hits especially the US, I get a lot of questions as regards to how to dress properly to handle extreme cold. Since fur is kind of out of the question for most people in North America and Europe,  I will stick to modern equipment and kit. Basically, the best solution is the layered system, which is kind of like peeling an onion. We are talking about these four stages:

1. The first layer, the thermals. This is dead important, the base of survival, so it is vital to choose the right material.

2. Second layer is some kind of a thinner shirt, wool or high tech yarns, or fleece. It is of no help if you choose material which doesn´t help to transport for example sweat between the layers, so for example, to have cotton here or on the first layer, that destroys the whole idea.

3. The third layer, depending on what you are going to do, hard physical work or staying relatively still, this is where you add on the down jacket.

4. The fourth layer will than be a Goretex 3 layered jacket with a hood or  a cotton parka.


On top of this you need normally 3 layers of gloves/mittens and at least 2 layers of head cover. Same idea as regards to your feet. Boots should have thick soles to do the work.

I especially want to put emphasis on the first layer. After using different types of thermal underwear for the last 25 years of a life in the outdoors, my conclusion is that the choice is a very personal one. Either you like wool. Or high tech yarns. A few observations though:

I have noticed that thermal underwear which are marketed by brands who primarily focus on extreme sports, like competitive skiing, are not made for users who are outdoors a long time. This type of underwear are far too cold and should only be used for short time competition. Definitely not for Expedition. These brands tend to dominate the market today. So, look out!

Good quality thermal underwear has to do with the machinery they´re produced by. Some outdoor brands are produced in a way that needed changes and developments are hard to do. An important question is, do they have their own factory and machinery to produce their own brand? Important!

So, regarding my personal opinion, wool or high tech yarns? I think wool does itch on and off.


Thermal underwear are for me with the most important items of gear. This layer is the most important aspect of your choice of how to dress on your Expedition or adventure. Or a day out in the woods. This applies whether we are talking Arctic or tropical adventures. For example, at this precise moment, together with Termo, I am trying to figure out the best thermal underwear to use on desert travel. Thermal underwear is at least as important on such an Expedition as in the Arctic. And as regards to which thermal underwear to use, the following has to be taken into account:

  • It has to be thermal underwear with unique channels of construction to both insulate and help regulate body temperature
  • Light weight
  • Highest quality yarns
  • Anti-bacterial treatment that is not wash away
  • Active fit
  • Flat-lock seams to minimize chaffing
  • Fast wicking

 Please do come with your own personal opinions in this interesting subject! I am trying to explain the 4th layered system in this film below:



  1. THanks for the tips! please provide direction on what or how to dress for 20 degree desert conditions in so cali. I ride motorcycles daytime and sleep in my truck bed open air. I dont have alot of money any suggestions? Thanks J

  2. I need to buy some thermal underwear and your article is very interesting but I don’t know what to buy, a be out in the cold for long periods it seems to me that synthetics beet anything else but how I find them? What the name of the material
    How I even look for or ask for it? I’ve been in sports goods stores and they don’t help much thanks!

  3. Hi Gladys! there´s many to choose from and I am not surprised sport stores are of no help. Generally their staff don´t have much experience from the outdoors. But there´s internet stores which can help. Where are you located?

  4. I’m trying to figure out the best type of thermal underwear to donate to the homeless shelters in my area. Temperatures are expected to hit -45 degrees Celsius in the next few days. As I would need to buy a lot, I also need something that’s economically priced! Any ideas? I’m in Canada…

  5. I wish I could help. Good thermals, new, will take you on a 100 Canadian….I would go for wool, stronger generally. Where are you, northern Quebec?

  6. Hei Mikael!

    Thanks for such a helpful post! I will follow your blog from now on? I live in Norway but I am soon travelling to Canada. Do you have any info about stores in Vancouver? Or internet canadian sites where I can buy and send to my new “homeplace”? I do not want to buy more material as I am going to spend a long season (probably 1 year), and that means I need to buy a little bit of everything. For me the most hard to find is the right shoes for extreme cold, and the right gloves. Any tips? Tack så mycket!! Arya

  7. Hi Arya, Röros ey, I just live don the other side of the border for quite some time! It is a very difficult question you have, so i suggest, once you get to Vancouver, a lovely city, find an outdoor store there. I am not really familiar with the Canadian scene! Good luck!

  8. Ive been myself many times at Funasdalen 🙂 (området). What about shoes? Do you have any you would recommend me for extreme cold? I land in Vancouver but my destination is Yukon :O I will try to find them on internet or stores. And maybe someone have them there? Thank you! A.

  9. I need more info like the name brand and where to get long underware for long periods of time in the cold not made of wool I work in the oil fields in north Dakota thanks

  10. Mikael, Found you while looking for immersion suits. My friend, is a fisheries observer on small Nova Scotia fishing vessels. In dry runs the suit issued is not easily deployed. Given how fast these vessels may take on water in an emergency she’s looking for alternative under and over garments that allow her to work while giving her some margin of survival if she can’t get suited up in time. Thx!

  11. Lately I have been getting questions whether I am affiliated with Termo Original and I am not. We did work together before, but I am looking for a new supplier. The reason is simply because the manufacturer is concentrating on another part of the company. Nothing else.

  12. Hi
    We are going to Arctic for traveling coming February 2015. We are looking for clothing that keep us warm. Please recommend. Thank you

  13. I live in Mongolia where we get -40 in the Winter. I use a synthetic first layer and the second layer made from Cashmere. Last layer MUST be a good 700+ fill down jacket. Socks: a thin synthetic sock and then Yak or Camel wool. Boots: -100 C rated Buffin boots are the best.

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