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Best Thermal Sleepwear (+ Backup) Socks

British Army Issue Extreme Cold Weather (ECW) Arctic Socks

British Army Issue (ECW) Arctic Socks


As always, we're looking at the British Army Issue (Extreme Cold Weather) Arctic Socks from the point of view of long distance trekking over tough terrain.

Test subject: Foot Size = 9, Foot Width = Medium
Test item: Size = Medium (5 - 8.5 UK size)
Kit Tests: Winter, Summer
Disclaimer: None required (item not provided by manufacturer)


Materials: Wool (Ecru = unbleached and untreated) 100%
Weight (Size Medium) 120g
Product Sizing Reference: Size 9 Foot = Medium
Manufacturer RRP (n/a) Instead, sensible price: ~ £7.00

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Scramble Review

Introduction: Why sleep in socks?

If you're walking hundreds of miles over multiple days and weeks, it's sensible to have a backup pair of socks. If you're carrying an extra pair anyway, why not sleep in them?

A sure fire way to trick your mind into thinking your body is warmer than it actually is (i.e. what we call "feeling warm") is to prevent heat loss at the extremities. The warmer we feel at night, the lighter our sleeping bag needs to be, and the lighter our load, the further and/or faster we can go. Since we've already got a spare pair, it makes sense to use them. In addition, sleeping in thermals helps keep ones sleeping bag cleaner and fresher for longer.

Alright, but why not just take an extra pair of trekking socks?

The main reason we recommend the ECW Arctic socks is, aside from being very comfortable, they're very warm for their weight, and in Winter at least, quite a bit lighter than our main trekking sock (Darn Tough's Mountaineering Sock). We do recommend taking a spare pair of lightweight liner socks (which helps reduce blisters from friction and reduces the odour burden on your main sock), but your main trekking sock (as an outer) should be enough for even the longest (multi-week) treks. Due to the low chance of requiring a backup, we suggest making the backup's primary function, "sleepwear".

Inside The ECW Arctic SocksInside the ECW Arctic Socks

Fresh & Clean

When covering long distances, ones feet are absolutely the most important thing to look after (everyone knows how debilitating battered, bruised and blistered feet can be). Looking after ones feet is essential; an inspection, vital repairs, a wipe-down and dry off, followed by a good massage is the least you can do for your feet after bashing them the entire day. After some fresh air, a good pair of wool socks will keep your feet warm (without overheating), dry (preventing any fungal issues), and fresh (due to wool's antibacterial properties); and ready for another day of abuse.

A close up view of the Arctic Socks' loop stitched innerLined with a loop-stitched padding for better insulation and comfort.

Why Wool? Some Woolly Benefits:

  • Wool is an excellent insulator with one of the highest insulation to weight ratios of any natural or man-made fiber;
  • It insulates when wet;
  • Quickly absorbs sweat and evaporates it into the air;
  • It doesn't retain odours and will freshen just with an airing;
  • The outer layer of wool fibers have a high concentration of fatty acids with anti-bacterial properties.


The ECW Arctic sock is quite light and airy outside a boot, and inside compresses down quite a bit to something like a standard, 3 season hiking sock (if familiar with Darn Tough socks, it's somewhere around their "cushion" to "full cushion" weights, at least in terms of volume).


Conclusion & Rating

Assuming one ventures out in cold as well as warm weather and wishes to avoid shelling out for multiple sleepwear configurations, it makes sense to wear effective winter thermals in summer. In Scramble's 2016 summer, 160 mile kit test, I had 10 comfortable nights' sleep wearing these socks with an Odlo thermal top and Rab's Power Stretch Pro Pants; the sleeping bag weighed just 438g (and there were some relatively cold nights on the peaks). In Winter these socks are ideal, and though they are not the best hiking socks, they have been a handy backup on a couple of saturated occasions.

So to sum up, these are a supremely comfortable sock to sleep in all year round: they keep your feet dry and warm (without overheating); are relatively light for their warmth; are hard-wearing, and they won't break the bank at around £7 a pair. Making the ECW Arctic socks, Scramble's top sock pick in the Sleepwear category.


Product Images


Rating (out of 10)

RRP Value *

* The value score is derived from two factors:
1) Competitive Market Price (CMP). This represents our judgement of a competitive online price point if we were to stock the item. e.g. if we feel we would need to sell an item at 40% off (i.e. 60% of its full RRP) to be competitive, then our CMP score will be 6/10.
2) Customer Value Price (CVP). We then make an honest appraisal of the maximum price we would be willing to pay for the item (and we're mean). So if we'd pay 80% of its RRP our CVP score would be 8/10.
We then average the two scores to get our final value score, which in our example would be 7/10.


Last Updated: 30/04/17

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