Sleeping Bags, Sleeping Mats and Air Beds
After a day of camping or exploring, crashing out in your tent is all you look forward to. The right sleeping bag should keep you warm and comfortable, whatever the weather outside the tent.
Sleeping bags work to trap stationary air
within the bag itself whilst you sleep, using your body as a radiator to circulate warm air without releasing it.
The best kind of sleeping bags are those with features that secure in this heat, whether that's from an exceptional filling that lofts well, baffles that seal out every cold spot, or the impressive hood that traps in air near your ears and neck.
When you buy a sleeping bag you will be faced with a wide choice of temperature ratings, seasonal ratings, and lots of numbers in general. This guide will help explain precisely what these mean for you.
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Why are Sleeping Bags ‘rated’ and what do the ratings mean?
Sleeping bags have ratings simply because what is a comfortable bag in for the Summer won't be substantial enough to use in Winter. Seasonal ratings are the 'traditional' way of selling sleeping bags before a method of testing called EN 13537 was introduced.
The reason that the EN135357 standard was introduced is there is a glaring problem with seasonal ratings, in that there is no one main way of identifying a season. A 'season' in Denmark will be different to a season in the UK, perhaps by 10 degrees- so what bag should you take?
The main advice to take away is that no-one should blindly buy a certain season of sleeping bag without looking at the specifics of what it can handle! Below is a 'general guide' you can look at for an idea of how sleeping bags are rated. As you can see, 1 season bags are great for hot conditions, and 3 and 4 season bags great for colder weather.
EN 13537 Ratings- Are They Better than Seasonal Ratings?
The problem with seasonal ratings is that whilst a 4 season bag is designed for extremely low temperatures, it will probably be quite hot and uncomfortable to sleep in in the heat of Summer. It is very hard to define a season alone.
In 2002, EN 13537 legislation came in which ensured that all manufacturers now use high-tech sensors on heated mannequins in bags to determine how cold the bags can get. This is to standardise how sleeping bags are sold, and get away from the very subjective 'Seasonal ratings'.
The tests gave:
An Upper Limit/The Lower Limit
—This upper limit is a temperature a man can sleep without sweating profusely. This is tested in normal ‘Summer’ sleeping conditions, so the mannequin doesn’t have a hood on, and has open zippers. The Lower Limit Temperature is the temperature a man could sleep at for 8 hours without waking up.
This temperature limit is at what temperature the bag will still keep you warm/cool before it starts becoming a matter of survival/extreme discomfort. At this limit, you are probably not as comfortable as you would like to be, but you should be able to sleep.
The Comfort level-
This is the limit that a woman could sleep comfortably at and is the temperature you can be comfortable in. Obviously, the widest range here is what you should be looking for, so you can use your bag in a variety of situations.
An Extreme Temperature
—this test is for emergencies only! The test shows the minimum temperature a standard woman can remain for six hours without dying in the cold! This is the maximum (lowest) coldest temperature that you could use this bag in without freezing. This won’t be a number you will feel comfortable at all (you might still get frostbite!) but you will survive.
The problem with EN 13537 is that although it is much better than a seasonal rating, the fact is that you can affect how you sleep just by being human! Lab tested ratings are all very well, but as any couple knows, one partner can wake up roasting in the night, whilst the other freezes.
Your metabolism, how long it has been since you last ate, and your general physiology will all affect the warmth a sleeping bag can offer you.
Do you feel the cold?
Some people feel the cold more than others, if this applies to you then remove about 5°C from the lower comfort temperature. For example, a bag with a comfort rating of 0°C might be better, if you are susceptible to the cold, than a bag that has a comfort rating of 5°C.
This could be due to many different factors:
- Older people tend to feel the cold more than younger people
- Females have a different sense of the cold to males
- Infrequent campers may be more susceptible to the cold compared to hardened mountaineers
- Poor nourishment or hydration can lead to poor homoeostasis management (the ability of your body to react to environmental changes and keep you at a healthy temperature).
- Larger built people will feel the cold less than those with a slender build
If the bag is being used in different physical environments then the temperature will deviate from the average or temperate norm. At higher altitudes, air temperatures are cooler (-1°C for every 150m gain approx.) so for UK mountains you would need to remove about 5°C from the lower comfort temperature before you even accounted for your own physiology! If you are sleeping in a tent, chalet, hut or out in the open air, wind chills and other factors can affect the temperatures.
Add into this where you will be using it (most likely not just one trip, but many, all at different times of the year!) and Sleeping Bags seem a bit more confusing than buying for a simple season, or picking the best extreme temperature rating.
Remember to choose your bag not solely on rating, but on it’s shape, features, review, insulating fill, and how it has been stitched together.
Down Sleeping Bags vs Synthetic Sleeping Bags
What is down?
- Down is the fine layer of fluffy feathers underneath the normal feathers on water fowl, usually geese or ducks.
- Duck down is cheaper than goose down, whereas goose down has more insulating power than duck down.
- Younger birds tend to be covered in down at birth, whereas older birds have a layer of a down.
- Younger birds' down is not as full and lofting as older birds', so cheaper down products tend to be made from the down of younger birds, whereas more expensive down garments will have been made with the down of older birds for improved quality.
- Eastern European down is generally the highest quality down.
When down is compressed, the filaments of the fibres create small air pockets that trap in air, and therefore heat. This is seen naturally with animals who need insulation.
Fill Ratings in Down
The American market uses a different rating system to the UK/EU. The general rule for conversion is 600 US fill power is in fact, 500 EU fill. (Generally take off 100 of fill power for an EU/UK conversion.)
Higher fill powers are also lighter in weight. Most insulated items containing natural down contain 80-85% down and 15-20% of feathers. Natural down is often a more bulky and heavyweight purchase than a manmade synthetic alternative and is therefore more costly.
Man made, synthetic insulation is made using polyfibres, the lab made equivalent of natural down.
Synthetics are used to attempt to replicate the warming and heating effects of down, without the bulk, and with the chance to achieve higher levels of breathability, all at a lower cost.
Although heat is circulated with ease, synthetic insulation does suffer from heat loss at a quicker rate than natural down.
Down or Synthetic Insulation- Which is best?
- Good value for money
- Less care required in cleaning and storage
- Poor weight to warmth ratio when compared to down insulation
- Bulkier than natural, high quality down
- Synthetic Insulation provides plenty of circulated heat with more freedom of movement. However synthetic insulation loses heat quicker than a traditional down fabric.
- Synthetic insulation performs better when wet unlike natural down
- Synthetic insulation is cheaper and easier to care for than natural down
- Synthetic insulation is heavier and bulkier, meaning you will need more pack weight to accommodate it.
- Extremely warm for its weight
- Extremely compressible
- Performs badly when exposed to dampness/wetness
- More expensive than synthetic insulation
- Care required when cleaning and storing for optimum performance
- Lacks breathability
- More expensive
- Needs to be kept dry
Avoiding Cold Spots in your Sleeping Bag
Garment construction can help aid insulation look for the following in your bag.
Baffle walls are the way an insulated item is constructed in ‘panels’. Baffle walls can be small or large. Narrow baffles allow the down to stay in place and prevent it moving, trapping in more air pockets and retaining higher levels of warmth. Zips can also be held in a baffle. Baffles are tubes of fabric added over the zips in sleeping bags and sewed in over seams, these cover off all the cold spots where heat could escape and cold could enter, keeping your body heat in all night.
Baffles that tighten above the shoulders also stop heat from escaping and cold from entering just like a hood.
Stitch Through Construction:
This is a construction where the stitching of an insulated item is both vertical and horizontal, also known as ‘crosswise’. This method of stitching has the result of making the down sit in small pockets, similar to the natural air pockets found on an animal’s skin.
It also prevents the down from slipping within the garment, where it’s effectiveness is diminished. The closer the stitching, the less ‘bulky’ the jacket will look, but the less warmth it will retain.
2 Layer Offset:
2 Layer Offset is used in sleeping bags as an alternative to stitch through construction, which can leave cold spots in the fabric, which is more of an issue in static use, such as sleeping, where less body heat is produced by the user.
2 layer offset garments are made so that the seams are sewn in the middle with insulation both above and below them. The insulation layer is then split into 2 layers, which provides coverage in the cold spots for additional warmth.
A sleeping bag liner will actually increase the temperature in your bag as well as helping to keep it clean. Liners can vary from pure cotton, to cotton/nylon blends or fleeces. The liner should keep you warm, but should also protect the bag.
By using a liner you also protect the bag from tears, spillages and other problems, and you can wash the liner as you travel if it does get wet.
Shop: Sleeping bag liners
The lining itself should be able to absorb your body moisture, whilst the outer shell of the sleeping bag will usually have a DWR treatment, so water and condensation beads off, or a windproofing treatment based on a impenetrable membrane. A reflective inner lining helps to reflect heat back onto your body.
Because these treatments provide a barrier against breathability, they tend to be used in bags designed for colder temperatures only.
Ripstop nylon is commonly used because it is both smooth to touch whilst also being abrassion resistant, whilst a brushed polyester lining is commonly used inside the bag for comfort and moisture absorption.
An inbuilt hood is already there and padded, waiting for you to fall asleep on it. The right hood will enclose in more heat for a better sleep.
The hood can be paneled, and a multi paneled hood or a hood with a multi-cord hood closure will feel almost tailored to the shape of your head.
To cut down on some weight, some sleeping bags keep a apocket for you to stuff clothes into to create your own pillow.
Left and Right Handed Sleeping Bags
For sleeping as a pair, some sleeping bags can be combined together to create one large sleeping bag.
All you need is to buy one bag with a right hand zip, and one with a left hand zip- and put them together! (The bags also need to be of a similar shape and size.)
This practice is a little outdated, and most sleeping bag suppliers do make double sleeping bags that open as a duvet for couples. The main resson to choose a left hand/right hand sleeping bag is simply to make it easier to unzip.
Remember that a right handed zip means that when you lay in the bag, the closure is on your right!
With a left handed zip, the closure is on your left.
Because you want the maximum had 'reach' you choose a zip the opposite side to your leading hand. You will notice that many of the bags are left hand zipped, this is because most of the population is right handed. However, you can choose any bag you like, just having a zip in the left makes it easier for lots of right handers!
Right handed? You need a LEFT HANDED zipping Sleeping Bag.
Left handed? You need a RIGHT HANDED zipping Sleeping Bag.
Shop: Left Hand Zip Sleeping Bags
Shop: Right Hand Zip Sleeping Bags
This is because if you picture yourself in the bag as a right handed camper, you wouldn’t be able to use your right hand efficiently to unzip the bag. If you have a left handed zip, you can unzip with much more ease.
Women’s Sleeping Bags
Women’s specific sleeping bags are designed to give more space to curves than a man’s bag and are focused on distributing the space where it is needed.
Whereas a man’s bag has room for broader shoulders, Women’s Sleeping bags have more space at the hips and bottom, with less space at the shoulders so heat finds it harder to escape.
Shop: Women's Sleeping Bags
Kids' Sleeping Bags
Kid’s sleeping bags, are in many ways very similar to adults bag’s. They usual have inbuilt pockets for storage of glasses or a torch nearby for those afraid of the dark.
Inbuilt pillows and hoods can add more comfort and make camping more pleasurable.
Shop: Kid's Sleeping Bags
Longer/Shorter Length Sleeping Bags
If you are above or below the 'average height' or consider yourself quite tall or small, then you may want to look at an extra long or short sleeping bag in order to acquire more leg room.
The Shape of the Sleeping Bag
Sleeping Bags come in a variety of sizes but the two main shapes are Rectangle and Mummy.
The Square/Rectangle Sleeping Bag
- Rectangle Sleeping Bags are a basic rectangle shape with thick padding, and are usually made from basic polyester.
- These are less expensive, and are suitable for light Summer use. If you take one of these onto the hills however, you will soon feel it!
- The Rectangle has plenty of space for your feet and head, but this becomes a negative in extreme cold, as cool air has more room to circulate.
- Rectangle bags can be doubled up for two people. If you want to do this you need to look for Left or Right handed bags. If you get a right side zip and a left side zip, they can then be attached together. Otherwise if you are right handed, use a left handed zip- and vice versa.
- Rectangle bags are cheap and cheerful, and can serve kids and adults well for brief, short, good weather trips away, ideally when you’ve got a car to bundle the bag into afterwards, but because of their weight and hefty size, lack of hood and roomy interior, are not ideal for long trips, treks and technical routes.
The Mummy Sleeping Bag
Shop: Mummy Sleeping Bags
- The mummy sleeping bag is the other common design. This is so shaped like an Egyptian mummy- wide at the top, tapering to slimmer feet. Instantly you can see that it won’t take long to heat up your feet at all.
- The snug fit is like being tucked in as you get into the bag, and the heat should stay in.
- Mummy sleeping bags benefit from hoods that can keep your heat in at the head.
- Because mummy sleeping bags are made with less bulk, they weigh less.
- These can be restrictive, especially if you are used to a rectangle shaped sleeping bag, however the design will keep you warm in almost any conditions.
A stuff sack, or stuff sack is a sack used to put the bag in after you have used it for transportation and weather protection .
It looks tiny, but with help, and use of the compression straps, your stuff sack will really pull the bag in tight so you can carry it with ease.
Most sleeping bags come in a stuff sack, but if they don’t, or if you lose it, GO Outdoors do sell sacks.
Shop: Stuff Sacs
Looking after your Sleeping Bag:
- The best way to maintain your sleeping bag is to use a liner. This will help keep it clean.
- After an expedition, take your bag out and clean off any stains with a sponge.
- Use a commercial cleaner or ask your local dry cleaner if they can help you clean it. If you have a sleeping bag with an inbuilt membrane or DWR you may need to proceed with caution.
- You don't want to spin it too hard.
- Zip it up and enclose the zips in their baffles.
- Don't use any kind of softener or detergent - particularly if the bag is made of Primaloft or similar. This can hinder any kind of DWR treatment that's been applied to the bag.
- Keep the bag open - ideally on a washing line to dry off naturally.
- If possible- keep it stored flat, or at least out of it's stuff sack so the inner fabric can stay lofted. This is particularly important with down which can clump together and result in cold spots.
Sleeping Mats and Airbeds
Sleeping mats are essential if you want a good night’s sleep, whether you are trekking, travelling, backpacking or heading to a festival.
Lightweight and packable to save space and weight, sleeping mats are designed to preserve body heat
as you sleep closer to the earth than usual, and to provide a barrier of comfort over hard or uneven ground.
Sleeping mats are either self inflatable, blow up yourself, or closed cell foam, which requires no work.
Designs are all very similar with sleeping mats, and most accommodate roll up straps to help prevent it bouncing back as you roll it away the next morning, as well as a stuff sac to keep it in one place, protected from dirt and debris on the outside of your rucksack.
Shop: Sleeping Mats
- Fabrics are nearly always synthetic with a foam body, although down sleeping mats are in existence, and the best sleeping mats have one non-slip fabric on one side and a softer side on the other, so you don’t budge in the night.
- The whole body should be strongly reinforced with a lamination and water repellent coating, such as TPU or DWR for the best weather protection from damp ground.
- If you get the right sleeping mat, combined with a sleeping bag, you're sure of a comfortable night's sleep
Closed Cell Foam (Classic)
- A closed cell is a classic mat that looks like a yoga mat, firm yet flexible. These are cheap, easy to carry and even easier to pack away.
- Closed cells refers to the construction if the mat, which acts as a cellular barrier against moisture.
- Closed cell foam mats can be single or doubles, thick or thinner, depending on what you want to pay.
- The doubles are even handy for solo travelers, for just a little more weight you can have a really thick mat.
Inflatable (by mouth)
- The alternative to a closed cell foam mat is a self inflating mat. These are made from a similar foam body to the closed cell mats, but they have an included air valve.
- You should be ale to inflate the mat by mouth, and it should only take a few minutes. The thicker the mat, the more puff you will need, but the more comfort you will get as an end result.
- Prices vary with self inflating mats as well, with thicker yet lighter foam designs costing more than cheaper, less padded mats.
- Self inflating mats are heavier than closed cell, so are better fior short trips away rather than exploration routes.
- Self inflating mats will also require a puncture repair kit for hemming those small holes that appear if you rest yourself too close to rocky ground.
- Look for a quick flow valve, which will ensure less time pumping air in and out of the bed.
Airbeds (by pump)
- Airbeds are available in single or double sizes and are ideal for sleeping on within the caravan, or for adding extra comfort to an existing bed. Airbeds can be hand pumped, or foot pumped to capacity with ease in seconds. It is essential to not pump an airbed with a tyre pump, as the excess pressure can cause it to explode.
- Some air beds come with their own inbuilt pump which is connected via a motor. The secret of a comfortable airbed is not to over-inflate it. Typically airbeds are created with vinyl for the floor facing side for durability and abrasion resistance, with a softer flocked upper for comfort. The disadvantage of an airbed is that there is no insulating material within the fabric, just air, which will conform to the ambient temperature of where you are sleeping.
- However, inside a caravan this should be less of an issue than if you are using an airbed outdoors.
Which airbed is most reliable?
Cotton-PVC is the toughest, as the material is stronger and the seams are larger and better sealed, however their ribbed design often deters customers as they are perceived to be less comfortable.
What other features are available?
The wider the valve, the quicker the airbed inflates.
Stoppered valves are rather handy, as they can be pushed in before the pump is removed, preventing air loss.
In-built pumps (hand or battery) may save space and the “who packed the pump?” question!
Can I use a car foot pump?
Generally not as they usually rely on the one-way valve built into the tyre. They will suck back any air they push out unless one of these valves is present. Some pumps may have an adaptor though so check.
Which pump should I use?
Electric pumps are by far faster than hand pumps, but all come with a variety of valve fittings (simply check that one of the diameters supplied matches the airbed purchased).