Understanding Sleeping Bag Ratings
If you did your homework in finding out the best way to choose sleeping bags and the types available, you may understand the importance of sleeping bag ratings .
Sleeping bag temperature ratings are there to help you pick the most comfortable one for your camping trip or any other outdoor activities.
There's three ways to understand temperature ratings, however, other considerations have to be made that can help you purchase the right one.
The Three Main Ways A Sleeping Bag Is Rated
There's no rating in place that's 100% accurate! Body weight, metabolism, age, how we feel the cold or heat personally, and what we’ve eaten are some of the important factors that prevents ratings from being measured for more than just the average user.
Seasonal Ratings
Seasonal ratings work very similar to how we find a tent advertised for the season (s) it is meant to be used for ( e.g. 3 season “spring, summer and fall”) . This works very well for tents 90% of the time, but cannot be as accurate for sleeping bags because of so many other factors to be considered, as mentioned above which I will explain a little more, further on.
Advertised seasonal ratings:
- One season: For warm temperatures which can include inside the home.
- Two season: Late of spring until the start of fall (Autumn).
- Three season: Spring, summer and fall (Autumn), but not winter.
- Four season: These are for those who encounter very low temperatures.
When we see these seasonal ratings we should only use them as a guiding factor to check other more important ratings. You can understand why this is not the best way to use for ratings as a complete buyers guide when you look at how temperatures vary around the world.
EN 13537 Sleeping Bag Ratings
The EN ratings (standard for Europe) were designed for companies that sell or manufacture bags in European countries. Many of the outdoor companies outside of Europe including the US are now using this method for ratings.
Sleeping bags with EN ratings have had various lab tests done using a mannequin. This helps manufacturers provide a universal rating for consumers instead of each of them creating different test's and ratings that could only confuse a buyer when purchasing from different brands.
Many state the EN norm for bags is not accurate enough. I agree it's not 100% but the industry is heading in the right direction.
If you see a bag that has been EN tested then you have a better idea of what temperatures it's suitable for.
Here's Marmots spin on the EN rating which explains simply and very well how to interpret them.
Sleeping Bag Ratings Advertised In the Specs
The most simplest and easiest way to know which temperature a bag is suitable for is how it's advertised in the Specs.
If a bag is advertised as a 30° F / -1° C then it will keep a user warm down to that temperature.
Many buyers have issues with sleeping bags not keeping them warm at the temperatures they were advertised at.
A lot of these problems will be due to various things which includes where a person is sleeping ( i.e. in a tent, tarp or outside), whether they have eaten, what they are wearing, the bag really does not work as its advertised, or other factors.
Summary And Points To Consider
As mentioned above there's no all inclusive rating that's 100 % accurate for each individual, however, the sleeping bag ratings above gives a buyer enough information to have the best estimate possible.
The next step would be to measure these ratings with other personal factors.
Other factors and tips
- Clothing worn: Wear a good base layer while sleeping and remove clothing if you get too warm.
- Eating: Make sure you have eaten well enough throughout the day and a couple of hours before you sleep.
- Hydration: Staying hydrated is also important because a deficiency of water and other fluids means that your body’s cooling and heating system is affected.
- Body temperature: Most people either feel the cold or the heat more when sleeping. If your a cold sleeper then buy a bag with a higher temperature rating than it's advertised for and the opposite for someone that doesn't need as much insulation. My girlfriend has a cover when its 28 C , while I could easily use a wet towel. We're all different!
- Types: There's various types of bags, features and materials that helps a sleeping bag insulate heat better. Learning more about these will ensure a buyer gets the right bag.
- Women: It's been researched and recorded that women do feel the cold more. Again, it's probably a good idea for a woman to choose a bag with a higher rating that needed.
- Liners: Bag liners definitely help improve warmth which will be sold separately from the sleeping bag. The great advantage of these is if a person gets too warm they can just remove it, easily.
More about sleeping bags
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