HOW TO CHOOSE A SLEEPING BAG

4. Choosing the right sleeping bag shape

Sleeping bags come in various shapes and sizes. Choosing the right shape might depend on factors such as personal preference (how you like to sleep) and the activity you’re undertaking (i.e. weight). It can also depend on who you’re travelling with – think double sleeping bags.

A rectangular sleeping bag, for example, will be bigger and heavier than a mummy-shaped sleeping bag. Because sleeping bags work by retaining the heat that our body generates, the less roomy a sleeping bag is, the better it will retain that heat.

And conversely, the roomier it is, the more heat or energy it will take to warm it up, and the less effective it will be at retaining that heat. So think carefully about how important these factors are for what you have in mind.

4.1. Mummy

This type of bag is slim cut, following the shape of the body, and a contoured hood. This shape reduces the overall weight and provides more effective insulation thanks to the lack of ‘dead’ space that your body needs to heat up.

4.2. Rectangular

This shape of bag offers the most spacious sleeping experience, closest to the one you’d have at home in a bed. It can be opened out as a blanket and so makes a good option for campervan trips. But this comes at the cost of increased weight and bulk.

4.3. Semi-rectangular

This shape strikes a compromise between a mummy-shaped bag and a rectangular bag – for more space to move about, but better heat retention.

4.4. Double sleeping bag or zip-connect

Some sleeping bags can be zip-connected to create a sleeping bag for two people, or double bag. The benefit here is in sharing warmth.

5. What material should my sleeping bag be made of?

Down vs. synthetic. It’s the age-old sleeping bag question. Should I choose a sleeping bag with a synthetic fibre fill, or one with natural down feathers? As always, there are pros and cons to both options.

5.1. Down fill pros

• Superior warmth-to-weight ratio
• Highly compressible
• Regains lofting capability after compression
• Retains insulation performance for years

These characteristics make down the best option for cold, dry conditions, year-round. If you’re going to be exposed to damp conditions more frequently however, then it’s worth considering a synthetic sleeping bag.

Please note: Salewa only uses Responsible Down Standard (RDS) certified down. The standard guarantees that our down and feathers only come from ducks and geese that are well treated according to high animal welfare standards with no removal of down from live birds.

5.2. Synthetic fill pros

• More affordable
• Retains insulation performance when wet
• Dries fast

The shell material and lining material on sleeping bags is usually made from lightweight, synthetic fabric with ripstop properties. For damper conditions, sleeping bags with a DWR (Durable Water Repellent) finish are a good idea, especially at the head and foot sections, which are more likely to come into contact with condensation.

6. How to choose the right sleeping bag temperature rating

All sleeping bags come with a temperature rating as an indication of what kind of atmospheric temperature it will keep you warm in.

Some sleeping bags provide a season rating to indicate insulation performance i.e. 1-season, 2-season etc. or summer/ winter sleeping bag. But most have adopted the ISO (International Standards Organisation) system for temperature testing.

But these are only guidelines, and there are other factors that affect how warm you are. One person will experience the cold differently from the next, so it’s important to know your personal sensitivity levels. Once you’ve determined the lowest likely temperature you’ll encounter on your trip/ adventure, you can select the best temperature rating for you.

6.1. Sleeping bag temperature ratings

• Comfort Temperature: indicates the lower temperature limit at which the average cold sleeper can comfortably sleep through the night.
• Lower Limit Temperature: indicates the lower temperature limit at which the average warm sleeper can comfortably sleep through the night. A person might have to add extra clothing layers to stay warm at this temperature.
• Extreme Temperature: indicates the lowest temperature the average person will tolerate for 6 hours in extreme cold. This is not about sleeping comfort. At this temperature, the person will feel cold all the time, but will reduce the chances of hypothermia.

As a guideline, if you’re a warm sleeper, you can refer to the lower limit rating, and if you’re a cold sleeper, then refer to the ‘comfort’ rating.

7. How to choose sleeping bag size

Sleeping bags come in a variety of sizes/ lengths to suit most people. It’s important to find a sleeping bag that suits your height.

• If it’s too short, then your head and toes will press against the hood/ foot box, compressing the insulation and compromising its performance.
• If it’s too long, you will expend extra energy warming the ‘dead’ space and also carrying the extra weight. Many manufacturers offer a range of sizes, at Salewa we offer long and short versions of our main sleeping bags.

8. What sleeping bag features to look for

Aside from the shape, fill materials, temperature rating and length of a sleeping bag, there are several features to consider, depending on the activity and environment you’ll be sleeping in.

• DWR – Durable Water Repellent finish is useful in damper climates and if tent camping. Ideally, this kind of finish should be PFC-free, so made without the use of harmful PFCs (per- and poly-fluorinated compounds).
• Cross-product connectable sleeping bags allow two bags to be zipped together to create a double sleeping bag for shared warmth. These can be rectangular sleeping bags as well as mummy shaped. Make sure however that the bag you want to connect to is compatible and has the same zip.
• Compression stuff sack will help keep the bag compact and reduce the space it takes up in your pack. Important: Never store your sleeping bag in a compression sack. They are best stored in a spacious, airy storage sack instead, so that the fill is not compressed.
• Zipper in the foot section is useful for using the sleeping bag as a warm layer to sit around a campfire, for example, or to provide ventilation if needed during the night.
• A functionally cut hood with easy-to-use drawcord adjustment is very effective at increasing thermal efficiency.
• A draft tube behind the zipper helps keep warm air from escaping through the zip, while a thermo collar around the neck also cuts heat loss from the bag.
• A good quality zip with an anti-snag zipper guard will prevent the teeth of the zipper from catching on the shell or lining fabric.
• Valuables pocket inside the bag for small items such as a watch or headlamp.

Note: to keep your sleeping bag cleaner for longer and for a quick way to add extra warmth, consider using a sleeping bag liner (see also: How to wash a sleeping bag)