Do You Need A Sleeping Bag With A Bivy?

Camping in a bivy bag is all about being outside under the stars and comfortable in your natural surroundings. A bivy sack will keep your sleeping bag dry if you don’t want to sleep in a tent, but in cool or cold temperatures you’ll want to add some extra layers to make your sleep more comfortable.

You should use a sleeping bag inside your bivy to add extra insulation from the cool nights while sleeping outside in the wilderness. Using a sleeping bag in your bivouac sack also increases the padding between your body and the hard ground making your sleep more comfortable. Consider a bivy as a tent in which case you would typically use a sleeping bag.

This may sound great, but bivy sack camping is not for everyone. It is an extremely minimalist style of sleeping out, which can be fun, but it will be downright uncomfortable if you are not adequately prepared. Let’s go through when you should consider using a bivy and what you should expect.

Photo 150841080 © Scott Biales |

Do You Need A Bivy With A Sleeping Bag?

Campers who use a tent generally do not need a bivy because the outside of the tent will keep your sleeping bag dry at night. The only reason to use a bivy if you are tent-camping is to add an additional layer of warmth inside your sleeping bag. 

The temperature inside a bivy bag can translate to an increase of around 10F for the sleeper. This is a lot if you are camping in cold, mountainous areas, so a good quality bivy sack will quickly become one of your favorite pieces of gear, even if you are tent-camping. 

Some types of camping will definitely require you to use a bivy bag covering. These are usually ultra-lightweight minimalist expeditions, solo campers in backcountry areas, cycle hikers, or winter snow cave campers. Anyone can try out the experience of sleeping so close to nature, but it definitely takes some getting used to, so it isn’t recommended for more than one night to start. 

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Bivy Bag Design

Like all camping equipment, bivy sacks have become quite high-tech. A few years ago, these sleeping bag covers were nothing more than a heavy-duty waterproof bag that covered your sleeping bag. As you can imagine, besides getting hot, there was no protection against the inevitable build-up of condensation inside a sealed plastic space. 

The great news is that things have changed, and instead of creating sleeping bag bivy sacks out of one type of nylon fabric, recent designs consider the condensation challenge. Incorporating a layer of breathable material on the top tier of the sack ensures that the bag is rendered breathable and far more comfortable inside. Many bivy bags also feature manual zipper vents along the sides of the bag that can provide instant relief without having to climb out of the bag to get some fresh air inside. 

Some bivy sacks have taken the simple design to the next level and incorporate features like a shielded headspace or an enclosure to block out bad weather. However, a bivy sack will always be a small enclosed space with the primary function of keeping the sleeping bag dry. It will never feel like a regular tent, and sleeping in a bivy can take some getting used to. 

Ever wonder why sleeping bags are so expensive? find out why having the right one will make your camping sleep much better.

Features To Look For When Choosing A Bivy

Being able to enjoy a great night’s sleep while outdoors may depend on how comfortable your bivy is. When selecting, keep a few key design features in mind, as these tiny shells will be the most significant layer between the elements and your body. 

While most bivy sacks are similar in terms of function, try to find one that will suit your personal requirements. For example, I am pretty claustrophobic, so I prefer a bivy with a larger headroom area. If you sweat profusely, you may need a bivy with extra zipper vents to effectively release condensation. 

These are some features that you need to check when choosing a bivy bag to suit your needs:

  • Zippers – some bivy sacks have armhole zippers so you can access your bag, etc., without getting out completely. There may be other zippers along the length of the bivy which can act as vents. 
  • Weight – although these bags are usually light, the weight of each type may differ because of the materials used. If carry-weight is a significant factor for you, then this is something to be aware of.
  • Waterproofness – this is absolutely key and will depend a lot on the terrain of the intended expedition. 
  • Straps – some people like a lot of straps and hooks, and others do not. You might like to check that the bivy has a strap to hold the sleeping pad in place or loops to peg it down. 
  • Vents – these may be zippers or some other mechanism in the design. If you need additional vents, check that the bivy you choose has enough without compromising waterproofness.
  • Size –  You may need a little extra wriggle room to not feel like you are trapped. 

If you like the thought of camping under the stars but want to be up off the ground consider getting a comfortable sleep in a camping hammock

How Do You Use A Bivy? 

Some adventurers love using their bivy and prefer the feeling of being at one with the environment rather than being limited to finding spots suitable for setting up a tent. If you are using a bivy to sleep for the first time, there are some tricks you should know that will make the experience a lot more comfortable. 

Let’s go through some steps that will make your sleeping-under-the-stars experience a good one:

Position Is Key

When selecting a spot to spend the night, look for a sheltered space where you will be out of the way. Remember it will be less likely that anyone will see you since you aren’t surrounded by a large tent, so find a spot where you will be safe and comfortable. Of course, ensuring that you are not in a dry ravine or stream is important because rain upstream could make you very wet. 

Peg It Down

Most bivy bags have peg attachment spots where you can peg your bivy to make it cozier. Doing so also keeps the fabric tauter in case of an unexpected downpour of rain. The material is more likely to retain its waterproof qualities for longer if it isn’t all bunched up. 

Strap In Your Roll Mat 

Whether you want to use the roll mat outside or inside the bivy, the choice is yours. My preference is always inside, and most bivy’s have handy straps inside to secure your pad to the bottom. This will keep you safely on top of your comfortable roll mat no matter how much you move around in the night. 

Stow Your Gear

Unlike a tent, there is not a lot of space where you will be able to store gear in case of sudden rain. The best advice is to put everything that absolutely must stay dry, like your documents and shoes, at the bottom of your bivy. That way, no matter how hard it may rain during the night, at least you won’t have to stick your feet into drenched shoes in the morning. 

Snuggle Into Your Bivy

Some campers use their backpack for a pillow. Push your sleeping bag into the bivy to create your own little camping cocoon. 

Close The Head Section Of The Bivy

You need to ensure that if your bivy doesn’t have an enclosed, vented headspace section, you secure the top around your head and only leave a space for your face. It can get bitterly cold if you don’t, but you also need to breathe, which can be the trickiest aspect of using a bivy. 

It is a good idea to wear a warm hat or balaclava to sleep, so you don’t have to close the top too carefully around the top in cold weather. Breathing inside the bivy will increase the amount of condensation that may occur on the inside. However, new breathable fabrics have slightly negated this problem, which was a real challenge in the past. 

Dry The Bivy Out

No matter how comfortably you slept in your bivy sack during the night, it is good to get into the routine of turning it inside out during the day. If possible, hang it up to air out. Any condensation that happened the previous night will form a film of moisture that will feel extremely uncomfortable when you use the bag again. 

The Cons Of Using A Bivy Bag

Although a good quality sleeping bag bivy sack will allow you to remain dry no matter where you sleep, what are the downsides to using one? After all, it sounds like a dream to be able to make a snug sleeping nest almost anywhere, so maybe you are thinking of giving it a try. 

The first and most important word of caution before leaving on your camping adventure is to check the weather. Wild camping is only fun if you don’t get caught in the pouring rain without a tent. Also, ensure that it hasn’t rained in the past few days before your trip because no matter how waterproof your bivy sack might be, sleeping on rain-sodden ground is sure to feel uncomfortable. 

Okay, so let’s go through the downsides of bivy sack camping:

  • You can only do this for a few consecutive nights. Sleeping outside without any shelter isn’t easy. While one hiker may love the sensation of sleeping under the stars, for another, it may feel like cruel exposure to the elements.
  • It’s not private. Unlike a tent, your sleeping body will be out in the open. 
  • You may get wet if it rains
  • You may become clammy and damp inside the bivy as your body heats up and the air cools down. Condensation may begin, which will cool you down.
  • You may get a lot colder using only a bivy for protection rather than a tent.
  • Although most do have a screened face area, you may still be bothered by insects more in a bivy sack than a tent.
  • Unlike a tent, you can’t store much of your gear inside a bivy bag

So ultimately, the type of camping you are planning to do will decide whether or not you will need a bivy for your sleeping bag. You probably won’t need one if you are camping in a tent, although a bivy may keep you warmer. However, if you are planning a minimalist expedition or wild camping without tents, you should invest in the best quality bivy possible to keep you dry and comfortable. 

Using a sleeping bag liner is another way to get some extra insulation and keep your sleeping bag clean if you don’t need the added protection a waterproof outer liner. Check out all the details in my recent article on all the benefits of having a sleeping bag liner

What’s The Difference Between A Bivy Bag And A Sleeping Bag?

A bivy bag and a sleeping bag are two very different pieces of equipment. Because they are usually used together, there is sometimes confusion. A bivy sack is a waterproof outer bag that your sleeping bag goes inside of.

Both are extremely useful pieces of camping, hiking, or survival gear. While you will almost certainly always need a sleeping bag if you are staying outside overnight, you may not necessarily require a bivy bag, especially if you are using a tent. If you are not using a tent, then you will need a bivy sack to keep you dry during the night. 

Let’s look at some of the differences at a glance: 

ItemSleeping BagBivy Bag
FunctionWarmthShelter – it is essentially a waterproof bag that slips over a sleeping bag
SizeBody SizeSlightly larger than a sleeping bag
TextureInsulated, light, and softWaterproof – to protect from the elements if not using a tent
Special featuresSleeping bags are intended to keep the user warm and fit snugly around the bodySome bivy bags have larger, enclosed areas around the head for extra breathability and protection from insects
Other usesSoft seating area when not sleepingIt can be used as a small tarp in bad weather

Should I Sleep In A Bivy Bag Or A Tent

So you may be wondering why anyone would only use a bivy sack rather than a small tent. There are a few excellent reasons that bivy camping is popular among some hardcore adventure campers. There are the following:

  • These portable, waterproof sacks are lighter to carry than a tent
  • A bivy will take up less space in your backpack
  • They are quicker to set up
  • You have an unobstructed view of the night sky
  • They are more discreet than setting up a tent
  • It offers a layer of waterproof protection in case it rains


A bivy is a useful item that keeps the sleeping bag dry during the night. If you are using a tent, it is not necessary to also include a bivy, although these light, waterproof bags can also be used as weather-proof coverings for other essential gear or even rucksacks. 

Using a bivy is essential for adventurers or bikers who are not able to carry a lot of heavy gear. These handy items make it possible to sleep almost anywhere with minimal equipment. 


Beau is an electrical engineer with a knack for DIY repair and construction. When he's not tinkering with his projects he's on the road travelling and enjoying an exciting lifestyle with his young family.

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