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Does a Bivy Sack Add Warmth

A bivy sack is a lightweight, water resistant covering that can be pulled over your sleeping bag to provide extra warmth and weather protection. But does it really work?

Some people swear by them, while others say they don’t make much of a difference. So, what’s the verdict? Does a bivy sack add warmth? Let’s take a closer look.

What is a Bivy Sack?

For anyone who doesn’t know, a bivy (short for bivouac) sack is basically like a tent you wear. Made of waterproof and breathable fabric, most models have an outer layer that’s tough and water-resistant and an inner layer that feels almost like silk.

Some bivy sacks come with bug netting (which you can zip open and closed depending on the temperature), while others are made to fit snugly around your sleeping bag.

Bivy Sack Advantages

A bivy sack’s primary function is keeping you dry, which makes it a great option for anyone who tends to have wet dreams or just enjoys taking advantage of mother nature’s water features.

However, it has some other benefits as well:

  • Bivy sacks are compact and lightweight, so they’re easy to pack in any backpack.
  • They fold up into their own pocket so you don’t have to worry about losing them . Some models weigh less than eight ounces!
  • You can find a good quality bivy sack at most outdoor retailers.

Most are made of breathable, waterproof materials that allow for efficient temperature regulation.

Bivy Sack Disadvantages

Even though there are some great benefits to using a bivy sack, there are some disadvantages as well –

  • Most bivy sacks can’t accommodate more than one person . If you have a partner, you might want to consider buying two separate ones.
  • They aren’t very versatile. Unless you’re okay with being stuck outdoors, they don’t really work inside your house or apartment.
  • It’s tough to set up camp with them as well. Granted, this is also true with some tents too. But it’ll definitely slow down your tarp-scaping abilities if the rain doesn’t let up.

Overall, it’s tough to say whether or not a bivy sack really works. They might add warmth, but they certainly aren’t as versatile as sleeping bags.

If you’re looking for something that can serve as your main source of shelter, you might want to consider buying a tent instead. However, if you’re looking to experiment or just want something lightweight to use on your next backpacking trip, a bivy sack might be exactly what you need.

But are Bivy Sacks Warm?

Many people swear by bivy sacks as a way to stay warm in cold weather. After all, if it works to keep rain and snow out , then it should work equally well at trapping your body heat inside, right? Well, that’s not always true.

The fact is that your body might actually sweat more while inside a bivy sack than if you were sleeping outside unprotected because of how small and enclosed it is – so much so that some hikers have even reported waking up soaking wet from condensation.

So does this mean a bivy sack isn’t going to keep you warm? Not exactly.

As with anything else, there are good and bad quality bivy sacks on the market. If you buy a cheaply made one without all of the insulation, breathability or weather-proofing, then it definitely won’t be able to retain nearly as much heat as a high-quality model. If you’re going to buy a bivy, then be sure you’re getting one that’s at least moderately warm.

Can Bivy Sacks Keep You Dry?

If there’s anything we’ve established so far, it’s that a properly made bivy sack will keep you dry more often than not. After all, waterproof and breathable fabrics are the whole reason they’re needed in the first place.

But just because bivy sacks can keep you dry, that doesn’t necessarily mean they’ll do it better than sleeping bags or tents. After all, if you choose to sleep under a tarp or with an open tent door , then you won’t even need your bivy sack.

In fact, most people find that bivy sacks can keep them drier in some cases and wetter in others.

For example, a bivy will do a better job of keeping your sleeping bag dry if it’s raining hard outside and you have no choice but to pitch your tent under a tree. However, it’s going to be pretty useless in a light drizzle where you can easily get inside your tent and close the door.

All things considered, the best way to get dry when you’re outside is still to pack yourself up into your sleeping bag or tent. And if that doesn’t work out, then maybe it’s time for you to invest in some rain gear.

Final Thoughts

From a pure warmth standpoint, bivy’s might not be as good as sleeping bags or tents because of how small and enclosed they are.

However, they work well for weather protection and as a substitute for a tent. A bivy sack does not provide nearly as much warmth as an enclosed or open shelter, but it works great for quick and dirty rain and wind protection.

Bivies also come in many different shapes, designs, and sizes. Some are waterproof while others allow water to seep through. Some are simple while others have many features, such as netting and waterproof zippers.

The right bivy sack can provide important protection in a wide range of situations.