The right sleeping bag temperature can make the difference between you and your mates spending an enjoyable, memorable night in the outdoors and spending the night shivering under the stars.
Common sense dictates that the thicker the bag, the warmer it will be. However, this isn’t true in the often difficult to understand world of sleeping bags.
This is because you can get bags with different insulating materials, some of which are designed to be extremely lightweight while being an extremely efficient insulator.
Think about this for a moment, your jacket probably doesn’t have a temperature rating on it and neither does your quilt that protects you in your comfy bed.
When it comes to sleeping bags, they normally come with a temperature rating; the rating however, is really more of a guide.
Everyone interprets cold weather differently, so it’s important to understand what exactly that elusive temperature rating actually means.
This guide should help you answer the question of “what temperature sleeping bag should I get?”
If you’re travelling around Australia for example, you’re going to need an entirely different temperature rating for the winter in Tasmania than you would if you were camping on Fraser Island, Qld in the summer.
Although Australia is a pretty flat country versus many others, you will still notice a difference in temperature up the top of the Blue Mountains, versus camping on the coast.
You’ll want to get the lightest sleeping bag that meets your needs, and it’s not a bad idea to get a bag that can protect you in colder weather than you expect.
Temperature Rating System
All temperatures listed in this section are in Celsius since Australians are smart enough to use the metric system for their calculations.
Now, a sleeping bag with a rating of 0 oC degrees would intuitively keep you warm in a 0 oC degree environment. However, that’s not really how the temperature rating system works.
Australia doesn’t have testing guidelines. This means that you really don’t have any consistency when it comes to bags sold in Australia.
Coleman bags use a “comfort rating” which indicates what temperature you can be exposed to and still be ‘comfortable’ whilst inside the bag. We have tested these ourselves to ensure that this rating is accurate.
There are generally four standards for measurement when it comes to sleeping bags. Take a moment to understand these rankings, and really get to understand what each measurement means.
Upper Limit: This is the maximum temperature a man can sleep without experiencing too much perspiration. The company measures this with the zippers open and the arms outside of the bag. You’ll want to pay attention to this rating if you’re going to be sleeping in the desert or in the height of summer.
Comfort: The temperature rating for the comfort rating is the temperature that the average woman can expect to sleep in a comfortable and relaxed position. If the temperature listed is five, then an environment within a few degrees of that should be comfortable for almost anyone.
Lower Limit: This is the average external temperature that the average man can sleep in the bag without waking up. It expects that the individual will be sleeping in a curled position to retain as much heat as possible.
Extreme: This the lowest temperature that any human can remain for six hours without risking hypothermia and death. It should be noted that frostbite is still possible. It is worth noting that the extreme rating is reserved for extreme camping when people are taking part in activities such as climbing Mt. Everest!
Depending on the manufacturer, you might not see all four ratings on the bag. Sleeping bags that are designed for the extreme cold may only list the extreme temperature or lower limit temperature rating.
Practical Considerations: Just Tell Me What to Get
Okay, all of this information is great to have and understand, but you don’t need to memorize this information before you go shopping.
Summer Bags: If you’re going to be sleeping in a warm, summer climate, then consider getting a +5oC degree bag. It’s light and is mainly designed to keep you safe from summer critters while you sleep.
Winter Bags: A 0 oC to -5 oC degree bag is the bag to choose for the typical winter in Australia. It’s a lot like having a flannel sheet and a few extra blankets on your bed. It never gets that cold in Australia.
All-Rounder: If you want a bag that can meet a variety of conditions, a 0 oC to 5 oC degree bag is your best bet. Most of us aren’t going to hike Mt. Everest anytime soon, and our guess is that an all-around bag is going to fit most camping situations. It’s going to feel very similar to having a doona on your bed.
When looking for a bag, you’ll want a bag that is rated about 10 oC degrees lower than the ambient temperature that you plan to sleep in. For a climate that gets down to 10 oC degrees, get a bag that is rated for 0 oC degrees.
You should also remember that the temperature rating is the rating that will wake you up. The closer you get to your “wake-up” temperature, the more likely you are to not sleep through the night.
Women’s Sleeping Bags
For any of you concerned about the distinction between men’s and women’s ratings, this isn’t really a gender issue. Rather, men and women have different body structures, which is why there are also bags that are specifically designed to match a typical woman’s contours. Research has also shown that women tend to sleep colder than men. True women’s sleeping bags have narrower shoulders, wider hips and extra insulation in the upper body and foot box.
While women’s sleeping bags are designed to accommodate the female form, some women may be more comfortable in a man’s sleeping bag and vice-versa. It really depends on your body shape, which is why it’s crucial to put the ego aside and try out both types of bags to discover the bag that fits you best. Women should focus on the comfort and the lower temperature rating.
Children also sleep colder than men, and you’ll want to be careful to choose a bag that fits your child. A bag with too much extra space won’t keep your child warm enough. Since none of us have the exact same size specifications, it’s important to realize that testing a bag is going to be really helpful to finding the right one for your situation.
When selecting a sleeping bag for a child, keep in mind that most novelty bags (ones with cartoon characters on them for instance) are generally summer rates and best used for sleep overs or in the height of summer as opposed to general camping.
Before purchasing a bag, it’s important to do your research. Talk with sales representatives and trust their advice. They have helped hundreds of people find the right bag for their situation, so don’t be ashamed to ask. It’s better to get a second opinion and get a bag that fits you. Remember that the temperature rating is not a hard and fast rule. A 0 oC bag isn’t a cut and dry rule, and you’ll likely still be warm if it’s about three degrees above or below that number.
If you’re an exceptionally tall camper or a shorter camper, the size of the bag will also matter. Make sure you check the dimensions and realize that a good bag should fit you with a little bit of slack from your feet up to your shoulders.
It’s also important to remember that if the bag keeps you too warm, you can also unzip the bag and let some air in. If the bag is too cold, there isn’t much you can do about the situation. There are also bags that are specifically designed for couples to share body warmth, which might not be a bad idea and can work well for couples who enjoy close quarters and the perfect sleeping bag temperature.