Use in the field

Insulation in sleeping bags works best when it is all ‘fluffed up’ and fully expanded. Once your shelter is set up, unpack your sleeping bag and give it a few shakes to get the expanding started.

Sleeping bags work best and last longest when kept clean and dry, so in the field, try to minimise the amount of dirt, sweat and dust that gets onto the bag [note]Hawks, Leona K., “Care of Down and Synthetic Sleeping Bags” (1990). All Archived Publications. Paper 210 URL = https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1209&context=extension_histall[/note]. Air your bag out after each use (in the morning over breakfast before packing up is best) – avoid direct contact with UV light for extended periods of time, but an hour of sunlight can help kill smell causing bacterial and fungal growth[note]Amichai B, Et.Al.,“The efficacy of sun exposure for reducing fungal contamination in used clothes.” (2014). Isr Med Assoc J. https://www.ncbi.nlm.nih.gov/pubmed/25167689[/note].

Treat your sleeping bag gently! Bags that are well cared for will stay warm for longer [note]Hawks, Leona K., “Care of Down and Synthetic Sleeping Bags” (1990). All Archived Publications. Paper 210 URL = https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1209&context=extension_histall[/note]. Do not use a good sleeping bag near the fire. All it takes is a single glowing ember from the fire to create a hole and damage the bag. Not to mention all the dirt, dusk and smokey smell that the bag will pick up. If you like having something to wrap around you at the fire, consider a lightweight fireproof thermal shawl or throw over instead.

A sleeping bag liner is a very worthwhile investment. Not only does it keep your sleeping bag clean and dry, but it provides extra warmth. Avoid sleeping in your bushwalking clothes overnight. Instead, change into nighttime camp clothes. This reduces body odour transferring to the sleeping bag and minimises the amount of oils or body sweat.

A few extra tips

• Give your bag a chance to fluff up especially on colder nights.
• If you are too hot in the bag, try un zipping it part way, take your head out of the hood or shake the bag to force out the warmer air.
• Try to minimise the amount of direct contact that your sleeping bag has with the ground. Use a ground-sheet if sleeping in the open, to protect sleeping pad and bag.
• When airing out your sleeping bag, hang it high off the ground, to reduce the chance of the bag getting dirty.
• Never force any zippers or buckles if they get stuck. Instead, be gentle and slowly undo any caught fabric.
• If using a sleeping bag without a hood, wear a hat or hoodie to keep warm and reduce the mozzies (if the shelter does not have a flyscreen).
• Wear clean clothes and be clean when getting into your sleeping bag.

Tips and tricks if you are feeling cold in your sleeping bag
If you are feeling cold then here are some tips to help

• Fully zip up your bag and use the hood.
• Ensure your insulation in your bag is inflated and evenly spread over the top of you.
• If rolling around, try to keep the bag from moving.
• Reduces air flow around the bag – block any drafts.
• Especially if you feel cold between you and ground than improve the insulation of your pad. Add clothing (or even your pack) between you sleeping pad and ground.
• Use a sleeping bag liner as this can increase temperature by up to 5 ℃.
• Wear a beanie to keep the head warm and loose fitting layer of warm clothes.
• Place your head inside your sleeping bag and breath inside the bag for about half a minute to warm up the air. Be mindful that your breath is also humid, so avoid doing this for long stretches as condensation inside your sleeping bag can be counterproductive.
• In an emergency scenario, you can use a foil wrap from your first aid kit for warmth. Be mindful again for condensation and water collecting on the foil and wetting your bag.

Sleeping with or without clothes on
There’s a lot of debate around whether or not wearing additional layers of clothing adds more warmth to the sleep system or detracts, with strong advocates on both sides and surprisingly little research on the topic.

A blogger called ‘onlinecaveman’ frustrated by the lack of information carried out his own DIY experiment to test the difference between heat loss wearing a layer of clothing versus not wearing a layer of clothing. He found that the system that used a layer of clothing lost less heat than the one with no clothing.

The main purpose of a sleeping bag is to create a layer of warm air around the body by trapping body heat, so any additional layers may enhance this effect. Sleep systems work best when the insulation is allowed to do its job, that is, the insulation isn’t overly compressed (i.e. too many clothes).

It seems the layering effect that we use with clothes during the day also works in the sleeping bag, however, avoid tight-fitting clothes (these can restrict circulation), and ensure extra layers are clean and dry. Also stay away from clothes with zippers or other hard or patterned sections that may cause pressure sores.