Buying advice sleeping bags: Find out everything important in our guidebook

Man in sleeping bag at sunrise

There are sleeping bags for camping or for hut tours, as blanket or mummy forms, with synthetic fiber, down or hybrid fillings. Sleeping bags can be short or long or have the zipper on the right or left and also be for the most diverse temperature specifications. Sleeping bags can be made of various cover fabrics and have different processing techniques.

For this reason, we have created this product guide to help you choose the right sleeping bag for you.


What temperature range should the sleeping bag cover?

The most important criterion for finding the optimal sleeping bag is the temperature range that the sleeping bag should cover. To do this, you need to know what temperatures to expect on your trips and what type of cold sensation you are.

Since 2005 there has been a standard for temperature specifications for sleeping bags. In general, there are three temperature ratings.

1. comfort range: the comfort temperature corresponds to a standard woman weighing 60kg with a height of 160cm, who is just not freezing.

2. limit range: this value is calculated for a standard man weighing 70kg with a height of 173cm, who just does not freeze.

3. extreme range: This value is calculated again with the standard woman under strong cold load, here there is already the danger of hypothermia.

Explanation of the temperature test

These standard persons lie dressed with medium functional underwear and the sleeping bag closed except for a breathing hole in the sleeping bag. The standard person is a dummy who does not move during the measurement, unlike the normal person. Why is this important to know?

A moving person exchanges ambient air, the sleeping bag is moved, air goes in and with it potential cold, and warmer air goes out. This does not happen with the dummy, so a blanket sleeping bag, i.e. a sleeping bag that is just as wide at the bottom as it is at the top with the same insulation, is just as warm as a mummy sleeping bag that is cut narrower at the bottom. Although, of course, in practice this is quite different. Here's what you need to know:

We humans, like our entire environment, are a product of evolution i.e. when humans feel cold and begin to freeze, in addition to the familiar physical phenomena (goose bumps, shivering, etc.) they will begin to concentrate on the body regions (torso, head) that are necessary for survival and continue to provide good blood circulation to these areas. The other areas (arms, legs, etc.) do not receive as much blood supply and thus do not warm as well. Since these areas are no longer warmed as much, they also no longer give off as much heat i.e. not as much space (sleeping bag space) can be warmed (principle of small oven large space). Therefore, mummy sleeping bags are warmer than blanket sleeping bags just not with the dummy.

Temperature ranges / influence

If we start from our latitudes, then we can roughly take four temperature ranges.

Average temperatures during the year
Season Date period Temperature range
Midsummer Beginning of July - middle of August Rarely colder than +10
Summer Whitsun - beginning of September Worst 0°
3 Season Easter - October plus winter storage Until -5°
Expedition or winter October - March plus altitude Individual

Of course, there are a wide variety of factors that influence the individual perception of temperatures and thus make the real feel-good temperature of the sleeping bag feel quite different than the warmth specification of the sleeping bag manufacturer often suggests.

Plus and minus temperature deviations in sleeping bags
Criteria Detail Deviation
Body weight More than standard Plus
Less than standard Minus
Wind force The stronger the more Minus
Carpet pad Standard=foam mat Neutral
Air mattress or similar Minus
Self-inflating mats Plus
Clothes Underwear Neutral
Light clothing Plus
Humidity Low Plus
High Minus
Body Fitness Exhausted Minus
Very trained Plus
Blood pressure Low Minus
High Plus

Another criterion is the altitude and the food intake for the actual temperature i.e. a well fed person does not freeze as fast as a hungry person.

The temperature drops per 100m altitude by ca.0,65° Celsius i.e. not only the latitude is responsible for the probable temperature, but also the altitude.

As an example: If it has +20° in Kathmandu (Nepal), it has approx. -4° in Everest Base Camp at 5350m altitude. In addition, it cools down much faster at night at this altitude due to the lower atmospheric density and a temperature of -15° is nothing out of the ordinary.


Which filling material is most suitable for you?

The next thing to clarify is which filling material (synthetic fiber, wool or down) makes the most sense.

Simplified, you can say that if you sleep in areas or conditions where high humidity is expected, then synthetic fiber is the right choice. If weight and pack size is important, down, provided it is dry, is the right filling. Wool as a filling is temperature balancing and rather insensitive to humidity.

Why are there different fillings at all and what can one do that the other can't?

Synthetic fiber...

has the property of absorbing no or very little moisture. At the same time it dries very quickly and is cheaper than down.


is an ideal insulator in dry conditions.

  • good insulation
  • low weight and pack size
  • comfortable even when it is warmer
  • wet down has almost no more insulation >drying process takes a lot of time

The ratio of down to feathers is given with e.g. 90/10 i.e. the filling consists of 90% down and 10% feathers. The higher the proportion of down the better the quality.

There are several methods to obtain down. The most disreputable method is the so-called live plucking, in Europe this type of down extraction has been banned since 1999. So that you do not buy down products that have been produced in Asia and were obtained with live plucking, there are various certificates such as Down Codex or Traumpass. The certificates are only awarded to those who can prove that their products do not come from live plucking.

Contrary to the opinion of many, you can of course wash down yourself. This is ideal with hand wash and hand warm water, which was added with a down detergent. After washing, the sleeping bag must be rinsed with clear water, squeezed (do not wring) and finally dried. This is best done on a normal clothesline.

We refer here to the care product producer Nikwax and its products.


is the perfect insulating material for a healthy and restful sleep. That is why the manufacturer Grüezi-Bag relies on wool as an insulating material in sleeping bags. The advantage of wool is that it is very temperature balancing, this leads to the fact that the temperature range in which you neither freeze nor sweat is very large. Because, as is known, whoever freezes does not sleep at all and whoever sweats sleeps badly.

  • Wool is climate balancing and provides a very good sleeping climate.
  • Wool is insensitive to moisture
  • Wool is light and can be packed small
  • Wool is antibacterial
  • Wool is a renewable resource


is probably the best insulation material currently available for sleeping bags. It consists of 70% RDS certified down and 30% wool. Thus, it combines the advantages of both materials. Due to the high down content, it insulates very well and is still very light. The 30% wool content makes DownWool naturally permanently insensitive to moisture and is also temperature balancing.

With its unique mix, DownWool combines the advantages of down and wool. Thus, the best insulation and a perfect, dry sleeping climate is achieved with a low weight.

  • DownWool insulates excellently
  • DownWool is climate balancing
  • DownWool is less sensitive to moisture than normal down
  • DownWool is antibacterial
  • DownWool is a renewable raw material
  • DownWool is light and can be packed small

The DownWool insulation material is only available in Grüezi-Bag sleeping bags.

Downwool composition down & wool

So what makes a sleeping bag more or less warm, or how do you achieve ideal sleeping comfort at a manageable weight?

Responsible is on the one hand thefilling and its quality, on the other hand the cover fabric used and the sewing technique, which holds the air and thus builds up an insulation.

Synthetic fiber, (mostly polyester hollow fiber) can be made in the simplest, simply "stuffed" into a loose cover, then the sleeping bag is sewn in various places a few times, so that the synthetic fiber does not slip immediately and ready is the "marvel". If you want a higher quality sleeping bag, it is of course made differently.

The filling is then siliconized hollow fiber with multiple channels, which is then processed into fleeces and built into the sleeping bag using shingle or another high-quality chamber technique. The hollow chambers provide for the stored air and the chamber technology for the fact that the synthetic fiber does not slip and/or that by the sewing technology no so-called cold bridges develop, as it would be the case if the sleeping bag is simply sewn through.

Here are the most important constructions for sleeping bags to obtain the best possible thermal insulation: Synthetic fiber and down

Stitched through

Simple and cheap, but cold, because the seam lets the cold in and the heat out.

Quilted sleeping bag construction
Shingle construction sleeping bag

Shingle construction

Significantly more elaborate, puffy and airy without cold seams are used in synthetic fiber.

H chambers

Used in down sleeping bags, the chambers are filled with down.

H-chambers construction sleeping bag
Inclined chambers principle sleeping bag

Inclined chambers

Principle as for the H chamber, but with longer connecting webs so that the cold penetrating through the seams has a longer path.

In summary, you can buy a sleeping bag that should withstand a temperature range of Comfort 0° both for 80.-€ and for 800.-€. The difference is in the durability, pack size, weight, origin and additional features that make the sleeping bag more expensive. (Water repellent, elastic, environmentally friendly production, etc.).

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