Across Sarek in winter - sleep system

English; Teori-Praktik The sleep system I used on my fairly cold ski trip across Sarek this winter worked better than any system I have so far used. I never slept better or warmer on any winter trip that I can remember. So I thought I'd share my system.

By Jörgen Johansson

Starting with the foundations I used a 14 mm EVA closed cell foam called Goodpad. This is a very priceworthy, high quality pad that is a good sized 600 mm wide by 1900 long. With pads 500 mm wide most people, not even a skinny beanpole like yours truly, cannot sleep on their backs with arms at the side without these limbs ending up un-insulated. With a 600 mm wide pad I can. Since I am 1910 mm tall the pad is almost long enough for me as well. Of course, everyone should trim a pad like this to fit their size and sleeping style. I've only trimmed the lower half, where my legs are, down to 400 mm in width. This brings the weight down to 400 grams.

On top of the closed cell pad I always use (even in summer) something that softens my night. So far nothing has even come close to comfort than the Thermarest Neoair. I use a size small, which is 1200 mm long. Since I use it for softness anything longer is in my mind completely unneccessary, since it is my hips and torso that needs the comfort.
I think the combination of insulative properties that the two pads brought, combined with the exquisite softness of a moderately inflated Neoair explains much of my excellent sleep. This was the first time I used the Neoair in winter and I had no problems with frost or ice inside, inspite of the fact that I filled it by use of mouth and lungs. I assume that remnants of moisture left after emptying it in the morning froze pretty fast since the mornings averaged about -15 C. But this was not noticable or did in any way I could detect infer with the function of the mattress. The Neoair Small weighs 260 grams.

The heart of the sleep system is of course the sleeping bag. I use a Western Mountaineering Ultralite Super which is graded to -7 or -9C (with collar). A very good sleeping bag for early, early spring and late, late fall, but not really a bag for Scandinavian winters. In spite of this I've used it in winter for several years, beacause I can beef it up with a quilt. I need the long variant, which harbors people up to 198 cm and weighs 885 grams.

This photo shows how I add a homemade synthetic quilt on top of the sleeping bag. The ripstop in both sleeping bag and quilt are hard to tell apart, but the back of the quilt is made of bug net which contrasts nicely.

The quilt was especially made for this trip, after testing the system for several years using my homemade down quilt. However, sleep systems in winter do suffer from condensation. The moisture that is given off by the sleeper and also by damp clothing that might be in the sleeping bag travels through the insulation. If we have a temperature of maybe 10-20 C inside the sleeping bag and -10-20 C on the outside, the moisture will condense somewhere in the insulation. In deep winter it will of course freeze.

This is particulary bothersome with down insulation. Synthetics handle this kind of moisture much better, but is heavier for the same amount of loft.

The above photo is taken in my tent on a trip last winter. As the sun was shining through the tent door I held the quilt up and shot a picture of it. You can see how the down (highest quality Polish goose down +800) is gathered in moist lumps and the sun shining through the fabric around them. This was after three nights of -10-20 C temperatures. Of course, the insulative properties of this quilt was not very good with the down in this condition. To restore it you have to get inside a heated building or be able to build a fire, both things not really an option going through Sarek in winter.

Obviously adding a quilt on top of your sleeping bag is not very practical if you toss and turn with your sleeping bag during the night, since the quilt might end up underneath you, where it won't do much good. Since I sleep on my side and turn inside the bag my quilt stays very nicely on top of me all night.

So this year I decided to go for a synthetic quilt, hoping that this combination would give me the best of both worlds; the low weight and high loft of the down and the more enduring loft of the synthetic insulation when exposed to moisture.

I had an old, homemade synthetic quilt that weighed 1100 grams, with only about 50% of the original loft left. Not an option. There are few makers of synthetic quilts that are light and warm these days. Fanatic Fringe seems to have gone out of business and Backpackinglight were sold out and their new line would not arrive until June. So I dug out the old quilt, opened it up at the seems and got two pieces of nice and lite ripstop nylon. This I kept and the insulation went to meet its maker (?).

My idea was to use the thin ripstop on top, where the DWR would shed moisture/frost that sometimes falls from my tent canopy, and on the other side of the insulation I would use a very light bug netting (25 g/sqm) I had come across. The theory being that it would ventilate better and weigh less than ripstop. In summer it might catch all kinds of debris, but since I wasn't going to use it except in winter, I didn't worry about this.

For insulation I choose Primaloft One (200 g/sqm) with a reported thickness. Both this and the bug netting was ordered from

As can be seen at the photo above I attached the insulation to the fabric using the time honored method by Ray Jardine; pieces of synthetic yarn were stitched through the fabrics and the insulation and knotted loosely (to let the loft remain unscathed) at 400 mm intervals. Since I had a bit of extra Primaloft I added an extra piece for double thickness where my torso would be, as can be seen above. Three thin elastics were added to hold the quilt in place on top of the sleeping bag.
I also knew that a safety pin that attached the quilt to the sleeping bag right below my chin was a very good way of keeping the quilt from slipping down towards my waist during the night. The weight of my quilt was 640 grams.

My insulative clothing is of course also a part of my sleep system. When having set up camp and retired into my tent at dusk I took of the BPL Merino Hoody that I used for skiing all day. Instead I donned my trusty old Woolpower pullover for something dry next to the skin. On top of this went the hoody, to dry it out as much as possible. I then donned my BPL Cocoon Pullover (see photo courtesy

This is what I used for my torso during three of the five nights. For the other two nights I added my down jacket, WM Flash. The Cocoon weighs 320 grams and the Flash 410 grams. These two jackets was quite enough to keep me comfortably warm during the day. I seldom used the Flash jacket except on cold mornings and evenings around camp.

 Below the waist I kept my BPL Merino Shorts. I took of my Paramo Cascada ski pants, added a pair of woolen Stil long johns plus the wonderful BPL Cocoon Endurance Side Zip Pants insulated with Primaloft. They weigh 365 grams. On my feet I added a pair of thich and dry Smartwool Mountaineering socks, put my damp day socks (Donner merino) on top of these and added a pair of gigantic nylon pile socks on top of it all.
With this gear plus gloves I slept warmly, softly and fitfully for five nights, the coldest being around -22 C, the warmest being -12 C.

Please comment at Utsidan in Swedish or below in English.


  1. Tidigare har jag sett fram emot alla era inlägg på Fjäderlätt men nu fattar jag ingenting eftersom min engelska är urdålig.
    Är det någon inställning jag inte gjort eller har ni helt enkelt slutat att skriva på svenska.

  2. Jörgen there is so much important information in this post it takes a couple of readings to digest.

    I agree completely about the Neo Air, the addition of an under mat is my approach too in winter.

    I have used down quilts for a while now but have not experienced the cold or moisture that you have, Though i have found a 15% increase in weight in my quilts over a 4 day hiking trip.

    I love mmy BPL Cocoon clothing and would not trade it for anything, it has not let me down for 3 years now.

  3. Great article, Jörgen. I tried different systems last winter, and some worked better than others. I am surprised to read that you wear synthetic insulation to sleep, I tried that but didn't find it too comfortable (might just be a mind thing, nothing wrong with the clothes).

    Did the evaporation/ condensation always freeze in the top synthetic quilt, or also sometimes (when it was warmer/ colder) in the layers underneath?

  4. Till Jan C,
    Jo, vi har i princip växlat till engelska, utom när det gäller artiklar som vi bedömer enbart har intresse för svenska läsare. Det är såklart tråkigt om vi på detta sätt tappar läsare som har svårt med engelskan, men vår bedömning är att vi ändå når betydligt fler läsare totalt sett om vi skriver på engelska. En lösning för våra svensktalande läsare kan ju vara att översätta till svenska mha Google Translator. Ibland blir det en del lustiga översättningar, men om man är insatt i ämnet brukar man kunna klura ut vad som egentligen menas.

  5. I don't know to what extent my down bag collected moisture during this trip, only that it did. It is seldom you experience such extremes as the one I photographed. But the moisture is there and it lowers the insulative properties. However, the quilt did collect LARGE amounts of moisture. Since it was so cold this was not immediately visible, the quilt seemed dry and lofted well. But when I laid my arms against the ripstop, for instance while sitting in my tent and writing in my diary, I noticed that the fleece gloves and the forearms of the down jacket got wet. Not just damp, but WET.
    One night I draped only the quilt across my waist and legs while cooking. I turned the ripstop towards my legs on the theory that I would dry the quilt out a bit and evaporation would be easier through the net. After 10 min I felt that my legs (in Cocoon pants) where really wet from thawed condensation coming through the ripstop. They dried out fast enough, but I was happy they were synthetic, not down.
    The bug net towards the pants did not lead to the same soaking effect, which I cannot explain, but of course feels like an added benefit.
    Hendrik, I use wool next to the skin so if the insulative clothing is synthetic doesn't bother me. I also feel comfortable knowing that not all my insulative gear is down. Bit of extra safety, sort of

  6. Att avstå från tidigare läsare och inlägg är ett val. Tiden kommer att utvisa om det var ett klokt val.
    Mången dubbel och trippelspråkig hemsida finns på nätet, tekniken och kommunikationerna underlättar det för läsarna, men givetvis med mera arbete för publicerarna.
    Intressant och späckad rapport om erfarenheterna från senaste Sarekturen. Tur att man hjälpligt läser engelska.


  7. Slutat att läsa på Fjäderlätt då det är Engelska!

  8. Det är såklart trist om du slutar läsa oss. Samtidigt är det kul om vi kan hitta nya läsare i länder där man inte kan svenska men ändå vill vandra här, eller i liknande miljö.

    Tiden får som sagt utvisa om det är ett klokt val av oss att gå över till engelska. Det är inte omöjligt att vi går tillbaka om vi känner att vi gjorde fel.

  9. Hello Jörgen. Thanks for your thoughts and shearing experience. I'm a big fan of modularity (i might thank Unix for that), saving money/resources and owning less stuff. So i wonder: what sleeping bag do you use in the summer, the WM Ultralite Super?

  10. Steffen,
    The WM bag is my fall/spring bag, in summer I use either a Marmot Hydrogen or a homemade down quilt. But the Ultralite Super might be the ideal allround bag for colder climates, especially if you sleep cold.
    On modularity I have an article coming up very soon where I look at a modular approach on other gear as well. It has sort of grown on me...

  11. Hej Jörgen,

    As I'm going to visit Hendrik in Finland this march I'm just going through my gear. I'm also playing with the thought of using a synthetic overquilt in addition to my 3 season down quilt. Most of my friends swear by VBLs but I'm not really tempted of laying in my own sweat. Have you ever had any experiences with a VBL or have you compared it with your two layer system? Really eager to know!

    Best regards,


  12. Hi Basti,
    No, I have never used VBL-systems. Some people really like them, but theys seem minority. Which does not mean that it is an inferior system, but at least proves that the 'standard system' must also work very well.
    A couple of years ago I met Rune Gjelnes, a Norwegian guy who has been to the North Pole and stuff like that a number of times. He was no fan of VBL-systems, but had on occassion used them in extreme cold. As soon as temperatures rose he prefered to skip them.
    So I will not diss the VBL-system, but I think you will do well without it also.
    Using a synthetic quilt on top of a down layer while sleeping means that the down layer will stay in much better shape after a number of nights out in winter. I find it excellent.

  13. How did the primaloft stand up to the use? Reason for asking is that it says on extremetextil that one should use a down proof fabric around it. Didnt you get a lot of small fibers flying around? I would like to use the material as an under quilt (a quilt under my hammock) and the up side would be against the fabric of the hammock so Im hoping to be able to skip an additional layer of fabric there. What do you think from your experience?

  14. The bugnetting I used on one side of the quilt worked very well. I used it as well on Finnmarksvidda a year later (see those entries). For winter use I can heartily recommend it. It is lighter and most likely breathes better than other alternatives.
    However, for 3-season use I would imagine that the netting could collect debris and this would probably eventually soil the Primaloft, lowering the insulative capacity. That is my theory, so for use year around I would protect the Primaloft using the lightest ripstop nylon I could find.
    You might not have this problem with a hammock, I have no experience of those, so just take my thougths as additional input before making your decision.


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