How to Stay Warm in a Sleeping Bag? (15 Great Tips)

One of the biggest enemies of campers is the cold! There’s nothing worse than getting all wrapped up in your sleeping bag looking for relief from the cold, only to find out it isn’t working out quite as you planned.

In addition to discomfort, extremely cold conditions can present dangers to your health such as hypothermia, so it’s super important that you plan ahead to ensure your sleeping bag can keep you warm all night long!

As such, here are some great tips to stay warm in a sleeping bag.

1. Choose your sleeping bag carefully

Buy sleeping bags

Choosing the right sleeping bag is a careful balance between making sure you’re prepared for the climate at your destination and saving on space and weight.

Check ahead of time on weather forecasts to see what kind of temperatures you should expect, and make sure you have a sleeping bag that is rated for at least that temperature.

Ideally, it’s best to find one that can perform at about 20 degrees lower; that way you know you’re totally covered.

2. Change into dry clothes

Dry and warm in tent

If you’re getting into your sleeping bag with sweat on your skin or damp clothes on, you can expect to be in for a chilly night. Moisture on your skin can wick your heat away and will cool you down as it evaporates.

To avoid this, give yourself a rub down and make sure to change into some dry clothes before slipping into your sleeping bag. The same applies to wet hair – avoiding any kind of evaporation is key to keeping cozy.

3. Dress for the occasion

Camper dressed for sleep

When you’re inside your sleeping bag, make sure to have as much as possible covered.

Any exposed areas such as hands or feet will be a drain on your body heat. Along with gloves and socks, make use of your sleeping bag’s mummy hood if it has one, or use a beanie or other head covering if not.

It’s also important not to overdress your core; wrapping up your core with too much insulation will isolate it from the rest of your body and leave your extremities feeling the frost. So make sure to insulate yourself evenly.

4. Think thermal

Woman in thermal wear

Thermal clothing such as tops, underwear, or leggings are built precisely for these kinds of situations. A solid thermal base layer will be much more effective than an additional layer of clothing and will weigh a lot less if you’re carrying spares around in your backpack.

A base layer of thermal clothing will act as a second skin to trap heat in, and also wick away any moisture or sweat to prevent evaporation chills.

Choosing between synthetic and organic base layers will come down to personal preference. Just bear in mind that natural wools usually take a little longer to dry out.

5. Wash your sleeping bag

Wash sleeping bag

If it’s been a while since your sleeping bag has had a good wash, it might be time to think about giving it a little TLC. Over time, they can become less effective at trapping in heat if the stuffing has started to clump together and bunch up. This can be caused by oils from your skin seeping into the interior and clinging to the filling.

A good spin in a washing machine on a gentle cycle, followed by a trip to the tumble dryer on a low setting can work wonders. Drying it along with other clothes or gear will help all that filling to break apart and distribute evenly, but if you don’t have access to one, just bashing it around by hand or with something like a tennis racket can achieve the same effect.

When the filling is evenly distributed and fluffed up in this way, it allows more air to become trapped between the layers, creating a perfect protective cocoon around you.

6. Sleep on insulation

Sleeping pads for tent

Staying warm in your sleeping bag is about more than just the bag itself. What you have under and around your bag can be just as important.

Placing a sleeping pad between your bag and the ground will stop your heat from being drained away and provide some crucial separation.

Most camping sleeping pads will advertise their ‘R-Value’ which tells you how well it serves as insulation. You should lookout for a sleeping pad with an R-Value of 2 or 3 at a minimum, but in conditions closer to or below freezing, you’ll be better served with an R-Value above 5.

In super cold weather, most people try to avoid inflatable mattresses – although comfortable, they can act as a drain on your body heat and cool you down rather than warm you up. If you can’t go without one, make sure to insulate the bottom well from the ground with something like a closed-cell foam mat.

7. Use an emergency thermal blanket

Emergency thermal blanket

Emergency thermal blankets work by reflecting thermal radiation, meaning you can redirect heat towards or away from your body as you see fit.

They are perfect for keeping you warm and can be used in several ways to add additional protection when you’re in your sleeping bag.

One option is to wrap them around you inside your sleeping bag which will give your body a solid extra layer of insulation. Another is to use it as a reflective layer underneath your sleeping mat to help to prevent the ground sucking away your heat.

The best thermal blankets get the balance just right between insulation and weight – check out our write-up on the best ones out there if you think they’d fit well into your camping setup.

8. Spread your clothes underneath you

Camping clothes

If you find yourself starting to feel cold mostly from underneath you, it’s important to do all you can to insulate yourself from the ground. Spreading out a layer of your backpack and clothes underneath you will help to put some distance between you and the ground, and will usually add some comfort as well.

If you’re using a short sleeping pad or air mattress to save on space and weight, you can use your backpack and clothes in the same way to make up the extra space at your feet. 

9. Pitch carefully

Pitch on grassy spot

In areas where the ground is cold, leafy and grassy spots are the best options for pitching your tent. Any natural insulation you can find will take pressure off of your gear to keep you warm.

Take a moment to pile up some leaves, grasses, or pine needles before setting up your tent on top. It will only take a few minutes, and can offer a crucial extra bit of help in keeping you warm.

10. Use a sleeping bag liner

Sleeping bag liner

A sleeping bag liner is something like a human sock that goes between you and your sleeping bag. They’re great for adding extra insulation to your sleeping bag and can make the gear you already have much more versatile without having to buy additional sleeping bags for different climates.

The best ones can add several degrees to the warmth rating advertised on your bag. They also help to keep your sleeping bag clean, which helps to prevent clumping of the insulation that would harm performance.

11. Get your calories in!

Camping snacks high in calories

Eating a snack high in calories before you go to sleep will provide your body with the fuel it needs to keep you warm throughout the night. In addition to charging you up, the process of digestion also produces heat of its own that can help to keep your temperature up.

Some of my favorite pre-bed snacks are peanut butter, pecans, or some butter mixed into a warm cup of cocoa.

12. Empty your bladder

Camping toilet

Every camper I know will be able to relate to this scenario: you’re snuggled up in your sleeping bag, all warmed up, and just about ready for a peaceful sleep when nature suddenly calls. It’s truly annoying to have to get out of your bag, and maybe even brave the cold outdoors, forcing you to warm up all over again.

It’s always better in these scenarios to heed nature’s call – any water inside your body will require heating of its own to keep it at the same temperature as the rest of your body. Wasting body heat in this way is not what you want, so always take preventative action!

Making sure your bladder is empty before you head to bed will help you dodge this scenario, and save your body heat from diffusing unnecessarily.

13. Get some exercise in

Stretching exercise outside tent

It’s important to remember that a sleeping bag doesn’t produce heat! They are designed only to insulate and preserve the heat of whatever is inside. So, the warmer you can get before slipping inside for the night, the more chance you will have at staying warm until the morning.

Alongside warming up beside a fire or stove, it’s good practice to get your blood pumping a little bit with some light exercise before you sleep. A brisk walk, star-jumps, or some sit-ups will fill your muscles with blood, get your heart rate up, and warm you up.

Try to keep it light though, you don’t want to break a sweat and end up with evaporation cooling.

14. Pre-warm your sleeping bag

Hot water bottle to warm tent

Using the same logic, it can help to pre-warm your sleeping bag by placing some hand warmers or hot water bottles inside an hour or two before you want to use it.

This will give you a solid head start and prevent your body from leaking heat to warm up the sleeping bag itself when you climb inside.

15. Snuggle up

Snuggle up in tent

Sharing the love can also mean sharing the heat when you’re camping. If you’re with a particularly hot-blooded partner or are one yourself, make sure to snuggle up!

You can even find couples sleeping bags or bags that zip together to give you the perfect spooning setup.

Hopefully, you’ve got some great ideas now about how to stay warm in your sleeping bag while you’re out on your adventures. By using a few of these methods, you will be able to stay cozy and warm all night long. In even the coldest climates, a few quick tweaks to your sleeping bag set-up can make a world of difference.