How To Make A Sleeping Bag Warmer?

Your partner or camping buddy suggests impromptu camping. You’re a bit conflicted about the idea, but then you can’t say no to the breathtaking beauty and tranquility of nature. How could you?

You’re facing a major dilemma, though–you’re not sure if your old sleeping bag will cut it when the temperatures drop at night. So to ensure you don’t freeze through the night, I’ll share a few tips on how to make a sleeping bag warmer that I swear by.

How can I increase the warmth of my sleeping bag? Follow these simple tips to keep warm in your sleeping bag. 

6 simple tips to keep warm in your sleeping bag

simple tips to keep warm in your sleeping bag

Get a sleeping bag liner 

This is probably one of the most underrated gears in the world of camping. Some people claim it’s a total sham and waste of money, while others say it works like a charm.

So do sleeping bag liners increase warmth? Simple answer – YES. However, the effectiveness depends on the material of the liner. Microfiber, thermal synthetic, merino wool, and Thermolite reactor are considered the best for adding extra warmth to your bag.

Besides boosting the warmth of your bag, these liners can extend the life of your bag by keeping it clean. As a bonus, you can use it as a sheet in shoddy hotels and even as a standalone sleeping bag during hot summer months. 

Wear warm clothing 

This is a no-brainer, really. But most people forget that nature has its own plans and can change in a blink of an eye. So pack your long johns, heavy socks, hand warmers, beanie, trusty rain jackets, and pretty much any clothing that would keep you warm at night. It’s always a good idea to be prepared for every possible scenario.

There’s no point of going into the wild to unwind and have fun, then end up cold and miserable the entire night. Tragic.

I highly recommend wearing several layers of clothing rather than one bulk sweater or jacket. Air, an insulator of heat, gets trapped between these layers, thus keeping the body warmer. Plus, you can easily remove or add a layer if the weather changes.

Pro tip: don’t bundle up too much, or you’ll start to sweat. The wetness will wrap you in a cold cocoon, making you feel colder. 

Use a hot water bottle

An old-fashioned hot water bottle can do all sorts of great things, boosting the warmth of your sleeping bag being one of them. This has worked for me time and time again. I highly recommend using quality bottles that are spill-proof and have a solid seal like the Nalgene water bottles.

If possible, avoid disposable plastic bottles as they can deform and leak when exposed to high heat.

Fill the bottle with hot water no more than three-quarters capacity and secure the cap. To avoid burn injuries and premature degrading of your bottle, never use boiling water. Boil the water, then give it a few minutes to cool before pouring it into the bottle.

Slip the bottle at the bottom of the sleeping bag before you hit the sack. This will keep you warm and toasty on a chilly night. If it’s too cold or you’re a cold sleeper, you can add a second bottle in the middle of your bag for a toastier night’s sleep.

Here is a video with a simple technique but one of the best methods to make a sleeping bag warmer.

Get a quality sleeping pad

You need a good sleeping pad to avoid the cold ground from sucking the precious heat out of your body. How much insulation a pad provides varies from bag to bag. An R-value usually categorizes these pads.

So the higher the R-value, the warmer the pad will keep you. It’s best to have a sleeping pad with an R-value of 2 or more. 

When camping in cold weather, I usually stack two sleeping pads together to create a double layer of insulation. It works like magic. I recommend using a closed-cell foam pad underneath an inflatable pad to protect the inflatable pad from punctures. 

If you don’t have two sleeping pads, just stuff clothes underneath the sleeping pad to get more buffer between your sleeping bag and the ground.

Don’t have a sleeping pad, or all your clothes are wet? No worries. Gather as many dry leaves as you can and place them beneath your sleeping bag.

Pro tip: Stay clear of inflatable mattresses. These inflatables lack insulation and won’t do your body any good when the temperatures drop.

Eat a proper dinner

Never sleep on an empty stomach when camping, especially in cold weather. Our bodies are constantly working, even through the night, so it’s essential to fuel it to keep our core body temp up.

Eat meals high in proteins, carbs, and healthy fats for dinner. These foods take longer to digest, thus raising your body temp.

It’s also a good idea to eat an energy bar or a healthy snack before you turn in for the night to keep your metabolism going.

Don’t take that shot of whisky; opt for a hot beverage like coffee or ginger tea instead.

And one more thing, empty your bladder when nature calls – holding it in uses extra energy to keep it warm. Get a pee bottle if you have to.

Snuggle up with camping buddy 

This is really self-explanatory…more bodies, more heat. One thing you probably didn’t know is that dogs make great snuggle partners.

Give it a try and see what I mean.

How to Keep Feet Warm in Sleeping Bag

If your feet often feel ice cold at night, here are a few toasty tips that can help you ward off the chill in your sleeping bag:

  • Use the good old hot bottle trick as directed above. It will keep your feet nice and toasty.
  • Layer your feet as you did on your body. Two layers of lightweight wicking socks would do. If it’s colder, consider three layers. Make sure you wear clean, dry socks to bed.
  • Stuff extra clothing at the foot end of your sleeping bag to give your feet more insulation. 
  • Always keep your feet dry. 


Can you put hand warmers in the sleeping bag?

Yes, absolutely. Put the hand warmers inside a pair of socks, place one at the bottom of your sleeping bag and the other in the middle before you go to sleep. 

How much warmer does a liner make a sleeping bag?

While it depends on the liner material, it can add about 5° to 15° F warmth to your sleeping. The three materials mentioned above are the best when it comes to providing additional warmth. 

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