Sleeping Bag Pre Heater

Sleeping Bag Pre Heater

Our latest tip discusses a simple sleeping bag pre heater to help keep you warm on those winter camping nights.

Staying warm at night in the mountains gets harder as we head into the colder months. This applies whether you are in a tent, mountain hut, snow shelter or bivvy.  Having a good quality sleeping bag and eating enough are key. It is also vital to insulate yourself from the ground. Another trick is to be as warm as you can when you get into your sleeping bag. For this some vigorous star jumps before bed work a treat! Oh, and making sure your sleeping clothes are dry is key too.

Even so, you’ll use energy warming up the insulation in that first few minutes after you get in. That’s where this top tip comes in. Using a sleeping bag pre heater really helps. It also feels luxurious too. Having your sleeping bag cosy for your arrival is a wilderness treat.  

My choice for such a sleeping bag pre heater has always been one of my trusty Nalgene bottles. All you need to do is fill it with very hot water and you are good to go. There are obvious safety risks associated with this.  Avoid using boiling water and ensure your bottle can withstand the hot liquid.

I really rate Nalgene bottles and have never had one fail in any context.  That includes the time I watched one slip out of my rucksack and career down a snow slope for several hundred metres. It even survived crashing into a band of rocks at the bottom of the slope! It is also a good idea to put the filled bottle inside a sock or wrap it in an item of clothing to further protect yourself.

Then just pop it into your sleeping bag about 20 minutes before you climb in. I guarantee it will be perfectly warmed for your arrival.  This works even better if you periodically move it in stages from the bottom further up the bag during this sleeping bag pre heater stage.

Of course, when you climb in you can also cuddle up to your Nalgene bottle and it will carry on keeping you warm for ages.  You’ll probably wake up in the early hours of the morning and find yourself cuddling a cold bottle of water. At that point I usually throw it outside my bag.  The exception is if the outside temperatures is so cold that it will freeze.  In that case I live with the fact it is better to keep it inside with me.

*Nalgene have now introduced a new 50% recycled bottle. Please check out all the details on our news page here.