By: Blonde Two

If you’ve ever done any winter camping, you’ll know the question of how to keep warm when camping is an important one. Not only does staying warm in a sleeping bag keep you safe on a cold night, it ensures that you will want to repeat the experience. Most winter campers (myself included) have spent shivery nights hovering in and out of sleep, and wondering if hypothermia has finally struck. There are lots of tips for keeping warm when camping (check out our ten ways to keep warm when winter camping) but the one I am about to share has come to me only in recent years.

How a down sleeping bag keeps you warm

It helps to understand how a down sleeping bag works. Each sleeping bag is filled with thousands (depending on the fill weight) of downy feathers. Each little down feather is made up of lots of fluffy fibres. The fluff is important not because it’s soft but because it traps lots of air. Air that can be warmed up to insulate you. But it’s not only the fluffiness of your sleeping bag that matters, it’s how it is constructed. More space inside the bag allows for more lofting (or fluffing up), which in turn traps more lovely warm air.

Sounds fabulous doesn’t it. But there’s a problem. Down doesn’t work as well once you’ve squashed all the air out of it.

Which gives us two problems really.

One you probably already know about. The compressed down you’re lying on won’t be keeping you as warm as the fluffed-up down above you. This is why we all spend so much money on sleeping mats (find out how to check the warmth of your sleeping mat here). No matter how warm your sleeping bag, you need a sleeping mat underneath you to compete with the cold from the ground from which all that squashed down isn’t protecting you. If you’re in a hammock by the way, you’ll still have the same problem. Some clever hammocks (for example my Hennessy Jungle Explorer hammock) have pockets you can insert a sleeping pad into, some clever hammockers invest in under quilts that hang underneath the hammock, and don’t get squashed.

Top tip – don’t squash that down!

The other problem (and here is where my keeping warm in your sleeping bag tip comes in) is that our instinct, when we are cold, is to curl up. This is, by the way, a really helpful way to spot chilliness in other people before it turns into hypothermia. If you’re out winter walking, and your companion starts hunching over, feed them something, suggest a warm drink, add layers, then get them moving.

Curling up if you are cold makes sense, which is probably why it’s instinctive. When body temperature starts to drop, protecting the core organs becomes a priority. By curling around them you are protecting them.

Which is all very well if you are a very small person in a very big sleeping bag (not actually a good idea because then you have too much air to warm up). If you are a normal sized person in a normal sized sleeping bag, as soon as you curl up, you’ll squash certain areas of down. If (like me) you’ve ever noticed that your bottom (often) and your knees (usually) are cold, it’s because you’ve curled up and squashed the down around them (let’s ignore the surface area of my bottom for now). What you need to do is work against your instinct, and uncurl yourself.

Want a cosy camping night?

If all this sounds a tad crazy, please feel free to ignore me. However if, right now, you’re wide awake in a tent, wondering why your bottom is so cold, and if you’re ever going to be able to get to sleep, please give my suggestion a go. That’s it. You can carry on shivering if you want (shivering is designed to warm you up) but uncurl, reach your toes down to the bottom of your sleeping bag, and feel those cold areas start to warm up.

You know you want to! If nothing else, it’s a cheaper solution to staying warm in your sleeping bag than buying merino knickers!