How important they are and how to choose the right one

Buying a sleeping bag can be overwhelming. There are a lot of things to consider: synthetic or down, mummy or rectangle shape, temperature rating, compressible weight and size. All of these options contribute to the most important (and basic) function of any sleeping bag: providing a comfortable sleeping experience after a long day of outdoor adventures.

For me (and I suspect most people), sleeping comfortably and well depends on not being too hot or too cold. No one wants to wake up in the middle of the night shivering or sweating. So how do you decide what type of sleeping bag to buy and how important, really, is the temperature rating?

The short answer is: pretty important, but like most things in life, making the best possible decision requires weighing several factors and combining those results with your personal preferences. To do this, you must first have a basic understanding of how temperature ratings are calculated in sleeping bags.

EN / ISO temperature ratings

If they are classified (and not all), the sleeping bags will have either an EN (European norm) or ISO (International Organization for Standardization) Evaluation. The good news is that the tests conducted by the two use essentially the same criteria: a heated mannequin dressed in a base layer and beanie on a foam sleeping pad. The test results produce the following “limit” temperatures – which are what you will find imprinted on the inside of your bag.

Upper limit

The upper limit refers to the highest temperature an adult male would sleep comfortably without excessive sweating.

Comfort limit

The comfort limit uses the temperature that an adult woman would need to get a comfortable night’s sleep.

Lower limit

The lower limit takes into account the lowest temperature at which an adult male could sleep comfortably.

And the extreme limit is the absolute lowest temperature that an adult female could survive. This note should not be used for the purchase of bags in general as this implies a very high risk of hypothermia.

These ratings are most often displayed in a combined text graph that ranges from highest to lowest temperature. One of my Rab bags lists the comfort limit at 39F, the comfort limit at 30F, and the extreme at 1F. This means that the average adult woman would find the bag comfortable down to 39F while the average man would likely be able to use the same bag in temperatures as low as 30F. The extreme limit of 1F is the lowest possible temperature at which the bag should be used (but only in an emergency).

The use by the male and female rating systems is based on scientific data which shows that women tend to be cold at higher temperatures than men and that adult men are often “hotter” than women. adult women. One of the reasons for this, according to studies, is that lower muscle mass on the surface of the body usually makes a person feel colder.

Another reason (if you like science) that just got published in a October 2021 study suggests that the set of women feeling colder than men is in fact an evolutionary characteristic related to having and caring for children (and this extends to species other than humans).

In order to determine the desired temperature range, think about where you will be using the bag. If you sleep outside in the summer and stay at a low altitude (without climbing mountains), a bag rated at 32 degrees Fahrenheit and above should work just fine. If you find yourself in an area where nighttime temperatures can drop below freezing or on an extended trip of several months, a 3-season sleeping bag that is between 20 and 32 degrees Fahrenheit would be better suited. And, if you’re into serious mountaineering where there’s going to be snow, you’ll need a real winter pack that’s designed for temperatures below 20 degrees Fahrenheit.

A lot of people I know always add at least a 10 degree buffer zone when deciding which bag to take where. For example, if they think they are camping in 32 degrees Fahrenheit, they will opt for a 3 season bag rather than a summer bag. You also obviously need to take your own body temperature trends into account.

Summer / Low Altitude: 32 degrees Fahrenheit and above

Not all bags have temperature ratings, and common wisdom is to assume that a bag without one will fall into the summer / low-altitude category – especially those made by mid-range or low-budget brands. The old adage “you get what you pay for” is often true of sleeping bags.

My go-to bag in this category is the Rab Neutrino Pro 200 with a comfort rating of 32F.

Rab Neutrino 200 sleeping bag – 349.95

Rab Neutrino 200 sleeping bag


$ 349.95

Neutrino Pro 200 Down Sleeping Bag – $ 400.00

Neutrino Pro 200 down sleeping bag

Neutrino Pro 200 down sleeping bag

rab. equipment

$ 400.00

The Neutrino Pro is a mummy-shaped, down-filled bag with an inner collar and drawstring. It is very small (12.6 x 6.2 inches) and weighs 21 ounces. Made with a water resistant and durable outer fabric, this bag stays warm even in the morning when there is condensation or dew.

I have used mine on numerous bike and backpack trips including a five month May-September trip through Central Asia from Mongolia to Turkey. Many mountains and desert regions played a part in this adventure and while there were a few sweltering nights in Turkmenistan where I slept on the bag with a bottle of ice water, I got enough sleep. comfortable for most of the trip.

Most notable were a few below zero nights in the Mongolian steppe where, although I also had to put on my Patagonia insulated jacket, I was still able to sleep.

3-season sleeping bags: 20 degrees Fahrenheit to 32 degrees Fahrenheit

The Big Agnes Star Fire UL 20F Down Bag, which features body mapping and vertical sidewalls to retain heat close to the body, is a popular 3-season sleeping bag with my hiker and biker friends.

Big AgnesStar Fire UL Sleeping Bag: 20F Down – $ 499.95

Sleeping bag Star Fire UL: 20 F down

Sleeping bag Star Fire UL: 20 F down


$ 499.95

Just like the Sierra Designs Nitro 800:

Sierra Designs Nitro 20 Degree Sleeping Bag – $ 319.95

Sierra Designs Nitro 20 Degree Sleeping Bag

Sierra designs

$ 319.95

One of the best features of the Sierra bag is its self-sealing vent for the feet when you’re a little too warm. You simply pull your knees up, then insert your toes between two overlapping layers of fabric to expose them to the outside air. When you retract them, the flaps close without drafts – at least that’s what many users of this bag have told me (the functionality of the sleeping bag is often a talking point for breakfast. at the camp).

Regarding the Star Fire, two of its main selling points are its warmth / weight ratio and above all its comfortable and fitted hood. Some of my male friends who have this bag say the dimensions (60 inches at shoulder level and 54 at hip level) don’t allow people with taller frames to sleep on their side, so if that’s you, this particular bag may not suit your needs.

Winter / cold sleeping bags: 20 degrees Fahrenheit and below

Because I’m one of those people who find a brand I love and stick with, my favorite winter sleeping bag is the Rab Neutrino 800 which has a temperature of -8F.

Rab Neutrino Lightweight Down Insulated Sleeping Bag – $ 399.95

Rab Neutrino Lightweight Down Insulated Sleeping Bag


$ 514.95

This is a mummy shaped bag with a water resistant outer shell, ideal for alpine adventures and mountaineering. I took this bag with me on my K-2 trek and was luckily warm sleeping in one of the most beautiful (and coldest) places I have ever camped.

I also interviewed some of my mountain hiking friends and one winter sleeping bag mentioned several times was the Northface Inferno 0F degree bag.

The North Face Inferno 0 Sleeping Bag – $ 520.00

The North Face Inferno 0 Sleeping Bag

The North Face Inferno 0 Sleeping Bag

The north face

$ 520.00

According to those who recommend it (and other REI online reviews), one of the best things about this bag is that it’s roomier than other mummy-style designs without sacrificing warmth. One of the reasons for this is that 800 Down is “enhanced with a hydrophobic finish that improves warmth by allowing it to dry faster and repel moisture ten times longer” than your normal mill cycle. Good on Northface for being able to improve on Mother Nature.

All sleeping bags included in this item are mummy style bags with down filling. In general, mummy bags are warmer because there is less space inside to heat and the heat your body generates stays trapped near you.

The fact that they are all bags filled with down correlates with the fact that I am a hiker, hiker, and cyclist who usually carries all of my gear with me. Down is lighter than synthetics and the packs are smaller. Down bags always have a higher warmth to weight ratio than those made from something synthetic.

Down, measured by “fill power” or its ability to inflate (fill space) refers to the plumage under the feathers of a duck or goose. This means that every ounce of down inside my Neutrino 800 sleeping bag fills 800 cubic inches of space. The downs (ha) of down include the price and the fact that if your down sleeping bag gets excessively wet, it will take a long time to dry (and won’t insulate well when wet.

Synthetic insulation, on the other hand, tends to weigh more and take up more space. They also break down (lose their warming abilities) every time they are packed in a bag, making them less durable than down bags.

If you are worried about where geese and ducks are in this scenario (like me), please be aware that most manufacturers including Rab, The north face, and Great Agnes, have adopted the Responsible Down Standards (RDS) in the making of their sleeping bags. So, confidently head into nature with your bags filled with down and a good night’s sleep.

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