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Sleeping Bag Hack

When you spend the night outside in autumn, it is easy to forget how cold an autumn night can be. Here we’ll tell you how to check which temperature level your sleeping bag is made for, and we’ll also give you a smart upgrade tip.

You can feel in the air that autumn is creeping in, so before you impulsively throw the small summer sleeping bag into your backpack it is (as always) a good idea to check the weather forecast and check the bag. Because how cold will that autumn night really be?

All sleeping bags must be rated according to the European temperature standard with the slightly bureaucratic name EN13537. If your bag is not marked with this info, a quick Google search of model and manufacturer will probably give you the answer.

The EN13537 standard has 4 levels, but only T-Lim and T-comfort are really relevant for ordinary hikers.


Indicates the lower temperature limit where one expects a standard man (80kg) to be able to sleep comfortably.


Indicates the lower temperature limit where one expects a standard woman (60 kg) to be able to sleep comfortably.

Nice and warm

If you choose the right sleeping bag, the chance of a good night's sleep is better.


Indicates the temperature limit where possible dangerous hypothermia can occur after some time (for example 6 hours) for a standard woman.


Indicates the upper temperature at which a standard man can sleep comfortably without sweating.

The temperatures are calculated on the basis that you are lying on a sleeping mat in a tent and wearing one layer of insulating underwear.

When we know that there are "warm women" and "cold men", it can be discussed how relevant this gender division is, but in general it is the case that women freeze more easily than men. If you know that you freeze easily, regardless of gender, you should buy a sleeping bag that can withstand 5-10°C colder temperatures than T-Limit/T-Comfort.

Hack Tips

If the sleeping bag turns out to be a little low compared to the reported night temperature, you do not necessarily need to buy a new bag. In many cases, it can be sufficient to use a thin liner bag as an extra insulating layer inside the sleeping bag.

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