Don't lose sleep in the wrong sleeping bag

This guide to choosing the right sleeping bag from our range will show you that warmth is the main thing to consider - but it’s not the only thing. Of course, in most conditions, warmth is your highest priority but you should also consider bag shape and how it is filled. 

When it comes to temperature, most decent sleeping bags follow the European Standard EN13537. This includes three temperature categories: T Comfort, T Limit and T Extreme. Here are what they mean: 

  • T Comfort: Comfort is based on a ‘standard’ adult woman having a comfortable night’s sleep. She is wearing one base layer in a relaxed position and, as the name of this category suggests, she’s comfortable
  • T Limit: Based on the lowest temperature at which a ‘standard’ adult male is thought able to have a comfortable night’s sleep. He is wearing one base layer but will sleep in a curled position to keep warm. ‘
  • T Extreme: This is a survival-only rating for a ‘standard’ adult woman and it is not advisable for anyone to rely on this rating for general use. There will be a strong sensation of cold which can only be endured for a limited time.

Of course, words can only describe so much and you might struggle to select the right bag based on those ‘T’ categories alone. That’s why it’s important to check individual product descriptions very carefully. All of the bags on our site are fully described and that includes minimum temperature limits. Always read this sort of information and feel free to contact us to tell us where you’re going and what sort of conditions you’ll encounter. We’ll help you make a choice based on those details. In fact, you should never buy a sleeping bag without expert guidance, unless you’re highly experienced in the outdoors.

There are other things to consider too when buying a sleeping bag. The shape is just one of them. For example, mummy-shaped sleeping bags are narrow at your feet and tighter around the body. This means there is less space around you, and the bag is deliberately designed this way. With less space to heat up, your body won’t have to work as hard to stay warm. A mummy bag also has a snug hood you can pull around your head for extra heat retention.

On the other hand, semi-rectangular bags are made for a variety of uses and temperatures. They have a tapered design that still gives you good heat retention, but there’s more space around your legs if you like to sleep on your side or if you tend to move around in your sleep. And then there are rectangular bags that are as wide at the foot as they are at the shoulders. They give you the most amount of room to move and are better suited for warmer climates, camping beds, or if you want to share your sleeping bag with someone else. 

One other thing to consider is how the bag was filled. For instance, A down-filled sleeping bag gives you the best warmth for weight. It’s lighter and easier to carry because of the compression factor. Down bags are also long-lasting, and will serve you well for a decade, or even more if you look after them properly. However, you should note that down is less water-resistant than synthetic fill so look for a bag with water-repellent down that sheds water and dries quickly. Waterproof outer fabric will be helpful too. Because down bags provide superb warmth at such a light weight, they are more expensive than synthetic sleeping bags but they're worth it. 

On the other hand, a synthetic sleeping bag is more appropriate for wet weather camping; the synthetic fibres are less affected by moisture and will retain warm air, giving you a high thermal performance even when damp. Synthetic bags are also easy-care options as they can be washed in the washing machine. On the downside, they’re heavier than down bags and not as compact and easy to carry.

It’s important to make the right choice as a better night’s sleep will assist physical recovery each day and put you in the right mental and physical space for the next day. As we said earlier, if you’re relatively inexperienced you should always seek professional advice when buying a sleeping bag and we are the professionals to call!