For those who enjoy nature and the mountain, the sleeping bag is an essential part of our team. A good sleeping bag will be our coat on the cold nights of the mountain and can make the difference between a good or a bad experience on the hill.
Understanding that acquiring a sleeping bag is an investment, choosing the right model should be done conscientiously and according to our needs. In that sense, there are several factors that influence the final decision: weight, volume, price and of course the temperature range in which its performance is optimal. In the following article, we will look at this last point and we will explain how the resistance of a sleeping bag is calculated, what the temperature ranges indicated on the labels mean and we will also give you some tips and considerations that can help you optimize the coat of your coat.
What temperature sleeping bag should I get? The sleeping bag temperature rating and sleeping bag temperature guide.
Nowadays, all the recognized brands submit their sleeping bags to the tests established by the European standard EN 13537, which was approved and accepted by the countries associated with the European Committee of Normalization (CEN) in the year 2002. Since then, all sleeping bags marketed in Europe are obligatory with this certification. This standardization was a breakthrough as it allowed an objective comparison of products, unlike what happened before its creation, where several brands, especially the United States, “estimated” the range of their coat based on the results obtained in the various tests proposed by ASTM, an organization that develops voluntary consensus standards for a wide range of industries. The problem with this standard is that the tests measure only the strength of the materials and not of the product itself, so the temperature given by the manufacturers was somewhat subjective since it was at their discretion and often far from the reality.
But, how does the standard set the temperature ranges?
The European standard EN 13537 defines a procedure that determines the limits of ambient temperature for the safe use of the sleeping bags with respect to their thermal properties, besides regulating the correct labeling of each model. It is worth noting that this standard only applies to stacks up to -24 ° C comfort, as the procedure does not consider clothing used for polar conditions or extreme altitude, so many sleeping bags designed for the Himalayas do not have this certification.
We can point out that the test is performed in a controlled environment chamber where it is possible to vary temperature, humidity, and air velocity. To now, there are three laboratories in the world (France, Germany, and Norway) where the sleeping bags are certified. To determine the properties of each model is used a standardized mannequin that is dressed in a T-shirt and trousers thin first layer.
The norm makes a difference by gender and for purposes of homogenizing the process considers that a “standard woman” is 25 years old, measures 1.60m and weighs 60kg and a “standard man” is 25 years old, measures 1.73m and weighs. To determine the properties of each model is used a standardized mannequin that is dressed in a T-shirt and trousers thin first layer.
The manikin is placed heaters and various temperature sensors and then placed inside a sleeping bag on a mat. Once the manikin is warmed to body temperature, the temperature of the air inside the camera and the surface of the manikin is measured for several hours.
From the measurements made, the insulation value of the sleeping bag is calculated and four temperature ranges are established which, if well interpreted, offer a good help in choosing the correct model. The four ranges are:
1. Upper Limit: The temperature at which a standard man can sleep without excessive sweating. It is set with the head out of the hood, arms out of the sack and with the clasps open. Generally, this range is not informed by manufacturers.
2. Comfort Temperature: The temperature range in which a female individual can sleep peacefully and comfortably, without the need for additional clothing and without feeling cold, using the hood and with the arms inside the sack.
3. Lower limit or transition temperature: It is the limit temperature at which a male can sleep without having to shelter, without trembling and without waking up for eight hours in a curved position.
4. Extreme Temperature: It is the temperature at which a standard woman can stay at least six hours without risk of hypothermia. It can be said that it is the survival temperature. When the extreme temperature is reached you can not sleep and the body is unable to rest.
EN 13537 provides a comparable and objective standard that serves to establish differences in performance between different models and manufacturers; however, there are several factors that influence the perception of the cold or the actual performance of each sleeping bag in different scenarios that are important to take into account.
Mattress: a percentage of the heat loss is produced by conducting to the floor, so if you plan to occupy your bag in cold or humid conditions, you should choose a mattress of a suitable R factor, that way you will optimize the comfort of your bag.
Carp: A tent can offer about 5 ° C of extra coat with respect to the exterior.
Clothing: European standard tests estimate the temperature range with only a thin first layer. In cases where the cold is intense, it is normal to sleep with second layers or even more coat, which considerably increases the range of comfort.
Liners: there are in the market internal sleeper bags that allow increasing the range of comfort in several degrees.
Size of the sleeping bag: If the size of the bag is too large in relation to the size of the user, the heat instead of being retained tends to dissipate, so the recommendation is that the size of the bag is according to the height of the person will occupy.
Gender: the norm establishes a gender difference since on average a woman feels colder than a male (approximately 5 ° C colder) because they usually have less muscle mass, which helps to produce heat body and that propitiates a faster metabolism.
Age: older people generate less heat and feel colder than younger people. In particular well-fed men between the ages of 16 and 24 have a high metabolic rate and it can be said that their bodies pump the heat so they do not feel cold. So for a young male, the comfort temperature could easily be 5 ° C colder than for an older man. Young children do not have the same natural heat controls as adults. The speed of their metabolism decreases as they grow, so it is very difficult to define temperature ratings for children.
Body fat: objectively, an overweight person has higher body fat which makes him a bit more resistant to cold than a lean person.
Physical condition: A trained person in good physical condition will be better prepared for the cold. Physical exhaustion limits the generation of heat.
Experience: A person accustomed to sleeping in the outdoors is more familiar with the cold, the equipment and with their own body. A beginner or people who live most of the time in the city, and with the comforts that implies, they usually feel colder than someone experienced or who is constantly going to the hills.
Food and hydration: when going on a trip to nature, it is essential to maintain good nutrition and hydration. A well-fed and hydrated person will generate more body heat and will be able to recover better from the effort made.
We hope this article will help you understand the temperature ranges of the sleeping bags and will help you to choose the one that best suits your needs. If you liked this post, Please Share!