Bivy sacks and bags are an indispensable piece of emergency equipment that everybody should have, and they can also be a weight-saving alternative shelter for ultralight backpackers. Emergency and backpacking bivy sacks are designed differently from one another, each with a certain type of functionality as its inspiration. The best emergency bivy sacks are lightweight, compact, and can save your bacon during an emergency situation. The best backpacking bivy sacks are durable, comfortable, and provide excellent ventilation. We’ve got the rundown on the best of each, as well as a few that excel in both realms.
After reviewing dozens of bivy sacks and bags we have identified the best for your emergency kits and backpacking gear collections. While sifting through the wealth of bivys on the market we considered factors such as heat reflection, weatherproof ratings, and durability in choosing our top picks, and then we provided a detailed list of many other great bivy options for your consideration.
We looked at many different bivy sacks and have chosen the Survive Outdoors Longer Escape Bivvy as our overall top pick. It’s the best overall because it is the most well-rounded bivy we found during our research, and it’s a great option as both an emergency and backpacking bivy.
In This Article
The 5 Top-Rated Bivy Sacks and Bags
|Best Bivy Sack Overall||Survive Outdoors Longer Escape Bivvy||4.3|
|Best Backpacking Bivy||Sierra Designs Backcountry Bivy||4.2|
|Best Budget Bivy Sack||Utool Emergency Bivy Sack||4.8|
|Best Ultralight Bivy Sack||Frog & Co. Tact Bivvy||4.5|
|Best Emergency Bivy Sack||Farran Outdoor Bivy Sack & Rescue Kit||4.8|
*Ratings are from Amazon at the time of publication and can change
Best Bivy Sack Overall: Survive Outdoors Longer Escape Bivvy
There’s always an exception to the rule, and the Survive Outdoors Longer Escape Bivvy is that exception as it stands on both sides of the fence that separates emergency bivys from backpacking bivys. It’s a durable and reusable bivy capable of withstanding many nights of use during your outdoor excursions, but it is also lightweight and compact enough to serve as an emergency bivy that you won’t mind carrying with you every time you head out into the great unknown.
The SOL Escape Bivvy’s capability and versatility are thanks in large part to the proprietary spun-bonded olefin fabric that makes up the bulk of its composition. It’s a quiet, tear-resistant material that is both waterproof and breathable. This bivy can be your stand-alone sleep system in temperatures down to 50 degrees Fahrenheit. No sleeping bag or liner is needed until temperatures drop further than that, and when they do you can rest assured that your sleeping bag will be protected from the elements inside of this bivy.
As a backpacking and camping bivy, the material has impressive durability, and the built-in zipper and drawstring closures are a nice comfort that’ll allow you to lock yourself in tightly during foul weather or loosen up the bivy for better ventilation. Whether you are recreationally camping or in an outdoor emergency, this bivy will reflect 70% of your body heat back to you.
There are more emergency-focused versions of this same bivy from SOL that will reflect 80% or 90% of your heat, but they are made of thinner material that is less durable than this specific model. All variants can be found by following the provided SOL Escape Bivvy’s product links.
Survive Outdoors Longer Escape Bivvy Key Features:
- Proprietary spun-bonded olefin fabric
- Weighs 8.5 ounces
- Reflects 70% body heat
- Zipper and drawcord closure
Best Backpacking Bivy: Sierra Designs Backcountry Bivy
You can comfortably sleep anywhere that has a small, flat piece of ground in the Sierra Designs Backcountry Bivy. This bivy has a much smaller footprint than a tent, and weighs less, but it will protect you just as well from mother nature while you rest inside of its confines. It measures 80 inches long by 36 inches wide, meaning that it can fit adults over six feet tall, and a guy line point provides the opportunity to keep it off of your face by tieing a rope to a tree for increased comfort. This is the regular-sized variant. There is a longer version available which measures 86 inches long by 40 inches wide.
The bivy sack is comprised of a 30D nylon ripstop bottom and a 20D nylon ripstop top. It’s durable where it comes into constant contact with the ground, but the upper material has been designed with breathability as the focus. The seams have been taped to ensure that wind and rain cannot easily get inside the bivy. This is a waterproof bag, for the most part, but strong storms can blow water in through the zippered opening and mesh window. The large U-shaped zipper provides plenty of room for you to get in and out of the bivy, and the mesh window is a fantastic feature for fair-weathered nights because it allows you to ventilate the bag and stargaze to your heart’s content.
The spacious design of this bag gives plenty of room for a sleeping pad and sleeping bag, and its 9.6-ounce carry weight is exceptionally light for all that this bivy has to offer. Most lightweight backpackers will find this to be a perfect companion piece to their minimalist and ultralight gear sets, and those new to bivy camping are sure to enjoy this bivy’s beginner-friendly comfort features as opposed to other backpacking bivys which some have said can feel like coffins. This bivy, however, with its guy out point and mesh window, does not have the same claustrophobic effect. It’s a comfortable and cozy way to spend a night in the great outdoors.
Sierra Designs Backcountry Bivy Key Features:
- 30D nylon ripstop bottom and 20D top
- Weighs 9.6 ounces
- Mesh window with rollaway flap
- Guy out point for increased comfort
Best Budget Bivy Sack: Utool Emergency Bivy Sack
The Utool Emergency Bivy Sack is a top-notch piece of emergency equipment that can serve as a backup bivy for extra cold nights on the trail, as an easy-to-store emergency bivy, or be transformed into a host of other useful emergency devices. As it is made from 28um tear-resistant fabric, it is more durable than most emergency bivys, and, although it cannot replace a true backpacking bivy, it can likely survive several uses out on the trail.
The best use for this bivy is as an emergency bivy that can be easily stored in a vehicle or a backpack for your adventures. We also think it’s a great backup option to have for camping and backpacking for those nights that turn out to be a bit colder than expected. Whereas most emergency bivys will need to be replaced after a single use, this bivy’s slightly thicker material should stand up to a bit more abuse. Utool also provides examples of other ways in which you can use this bivy during emergency situations, giving examples such as an emergency poncho, a makeshift tent shelter, and a rainwater collector.
This bivy measures seven feet long and three feet wide. It’s windproof and waterproof, and its mylar interior reflects 93% of your body heat back to you. It doesn’t have any ventilation options other than the opening in which you use to get in and out of the bag, so condensation is likely to build up throughout the night. We think this is an all-around excellent emergency and backup bivy, and the fact that it is inexpensive makes it an incredible value that shouldn’t be missed.
Utool Emergency Bivy Sack Key Features:
- 28um tear-resistant material
- Reflects 93% of body heat
- Weighs 4.9 ounces
- Measures seven feet long and three feet wide
Best Ultralight Bivy Sack: Frog & Co. Tact Bivvy
Whether you use it as an emergency shelter or a sleeping bag liner, the Frog & Co. Tact Bivvy is sure to keep you warm with its HeatEcho reflective polyester construction. Weighing in at a meager 4.8 ounces, it’s among the lightest bivvy’s we’ve seen, but it is also quite large and incredibly warm. The bivy sack measures seven feet long and three feet wide when unfolded, and it packs down smaller than a can of soda. It is available in green and orange colors, giving you the choice of whether you want to blend into the natural environment or stand out for emergency situations.
The bivy bag comes packed in a multifunctional stuff sack. The stuff sack itself keeps the bivy compact and secure, and the corded enclosure is actually a strong paracord that can be used as a rope in an emergency situation. That paracord also has a purposefully-designed fraying end that can be used as tinder to start a fire when you are in dire straits. Additionally, a 120-decibel emergency whistle is connected to the paracord so that you can grab the attention of rescuers or potentially scare away any dangerous wildlife.
The bivy sack itself performs like most emergency bivy bags. It is tear-resistant, but it is not durable enough for regular camping use unless you treat it with the utmost care and use it as an inside liner for your sleeping bag. This inside-liner method will help keep you warm and protect the bivy, but it leaves your sleeping bag vulnerable to wet weather and the dirt. The bivy is highly reflective and is a great option for emergency use. However you decide to use it, you can try it out with confidence thanks to the company’s six-month any reason refund policy.
Frog & Co. Tact Bivvy Key Features:
- HeatEcho reflective polyester film
- Reflects 90% of body heat
- Weighs 4.8 ounces
- Six-month any reason refund
Best Emergency Bivy Sack: Farran Outdoor Bivy Sack & Rescue Kit
The Farran Outdoor Bivy Sack & Rescue Kit is the best emergency-focused bivy sack on the market, and we think it’s the best option to keep for emergencies in your outdoor gear arsenal. This is not a reusable bivy designed for frequent camping use. Rather, this is an ultralight, ultracompact mylar bivy that should be used only when all other means of shelter and survival have been exhausted. That is how this bivy sack excels, and you should look at our other top picks if you want a product that is more durable and intended for camping.
Comprised of highly-reflective mylar, this bivy sack returns 90% of expelled heat to its occupant, and it is also completely waterproof and windproof. Mylar is crinkly and loud, and it is easy to tear, but it is exceptional for its heat retention and compact storage capability. As a result, this weighs less than our ultralight pick while maintaining the same seven-foot by three-foot dimensions, but you will find it near impossible to repackage once it has been unfurled and it will likely tear after a night out in the bush. A one-year warranty is provided with the product that covers manufacturing defects.
Included with this emergency bivy sack is a suite of other emergency safety tools. A 550-pound paracord functions as the stuff sack’s drawstring, and an emergency whistle has been attached to that. Additionally, a water filtration guide has been imprinted on the stuff sack to give you guidance during an emergency scenario. This is an invaluable piece of emergency gear that everyone should have.
Farran Outdoor Bivy Sack & Rescue Kit Key Features:
- Aluminized polyolefin construction
- Reflects 90% of body heat
- Several safety tools included
- One-year warranty
Who Should Buy a Bivy Sack
Emergency bivy sacks are a lightweight, inexpensive, and small piece of emergency survival equipment than everybody should have. They can be a life-saving shelter during a cold night or a thunderstorm when you find yourself stuck in the middle of nowhere without any help. Whether you store it away in a backpack or your car, an emergency bivy sack is a fantastic piece of gear to have while you travel in case you need it, but hopefully, you never will.
Backpacking bivy sacks, on the other hand, are meant for minimalist campers and backpackers who want to shed weight from their backpacks and reduce their camping footprint. Bivy sacks are used by mountaineers, winter backcountry explorers, and cross-country backpackers who want a simple sleeping solution. They don’t take up as much space on the ground as a tent, and so they are easier to use in more backcountry locations. Using a backpacking bivy is just like cowboy camping under the stars, but you’ll be protected from rain, wind, and bugs. Are you ready to give a bivy a try?
Important Features to Consider
There are a few important considerations to think through before purchasing a bivy sack.
- Backpacking, camping, or emergency use. Emergency bivy sacks are exclusively designed for emergency situations. If you want a camping or backpacking shelter than you can use many times without concern, you should purchase a backpacking-style bivy. People have made the mistake of purchasing emergency bivy sacks with the intent to use them as a regular piece of their camping gear only to discover that the emergency bivy would deteriorate and become useless after one or two uses. There are a few exceptions to the rule, but it is better to be safe than sorry.
- Emergency: mylar or polyester. Virtually every emergency bivy sack says that it is constructed of highly reflective mylar or some type of polyester film. Don’t be fooled by the marketing lingo as they are the same material. Mylar is a stretch polyester film, a type of plastic. Emergency bivy products may advertise that they are made from a certain type of material that is more durable and tear-resistant, but they are all essentially made of the same plastic material. To reiterate, the purpose of an emergency bivy is for emergency situations and you should not expect any of the materials in these products to last through several nights of camping. We’ve noted the few exceptions we found that were designed to be reusable.
- Emergency: size. Be sure that you choose an emergency bivy that is large enough to fit your body type. The worst time to find out that you purchased a bivy that was too small would be during an emergency situation. Some bivys are large enough to fit two adults at a time which can be an option to consider if you often travel with a partner.
- Backpacking: sleeping bag cover or all-in-one. Backpacking bivy sacks are available as thin, waterproof shells or full-on insulated sleeping bags with a water-resistant shell.
- The thin covers can be used inside or outside of your sleeping bag depending on the circumstances. Inside, they will keep you warmer while protecting your sleeping bag from condensation. Outside, they will protect you and your sleeping bag from the elements but may accumulate some condensation that will get your sleeping bag wet. Though thin, they are much more durable than any emergency bivy could ever hope to be.
- Sleeping bag bivys are larger, heavier, and can essentially replace the need for a sleeping bag. They may feature built-in padding of down or synthetic insulation.
- Ventilation. Emergency bivys do not have ventilation options. The only vent in an emergency bivy shelter will be where you get in and out of the bivy sack. Backpacking bivys, however, often feature zippered vents near the feet and have sliding zippers along the sides or front of the bivy that can be used to ventilate the sack when the weather is fair. Ventilation is key to reducing condensation.
Frequently Asked Questions
What is a bivy bag and how does it work?
A bivy bag is a lightweight bag designed to keep a person warm and protected from the elements. There are two primary types of bivy bags.
Emergency bivy sacks are extremely lightweight bags made of polyester mylar that are meant for emergency situations where a person is left without shelter. These emergency bivy sacks often feature highly reflective interiors that lock your heat inside of the bag. Their exteriors are waterproof and windproof. Emergency bivys are intended to be one-time use emergency shelters that are so small and light that carrying them in a backpack or keeping them in a car is a negligible burden. They are not durable, but they will keep you alive through the night during extreme circumstances.
Backpacking bivy sacks are designed to achieve the same results as an emergency bivy, but they are also designed to be durable so that a backpacker or hunter can use them night after night. These backpacking bivies often feature tough waterproof bottom fabric and softer, breathable water-resistant tops. Some are completely waterproof. Comfort is also a concern with backpacking bivies, and some have been designed with convenient features such as multiple zipper slides, adjustable visors, and plushly padded interiors. They are a lightweight and minimalist alternative to backpacking tents and camping tents. There are also bivy tents which are tight one-person tents shaped like a bivy, but we haven’t included those in this article.
Are bivy sacks warmer than tents?
This is highly subjective depending upon the tent, the bivy sack, and a wealth of other factors. Generally speaking, a tent provides moderate protection from wind and rain and does keep you about five degrees Fahrenheit warmer than no tent would. Most bivys will fully protect you from the wind and rain and will keep you about ten degrees warmer than you would be without a bivy.
Are bivy bags waterproof?
Nearly every bivy bag is waterproof or water-resistant, but not all. Emergency bivys tend to be completely waterproof and backpacking bivys usually have waterproof bottoms and water-resistant tops. If you want to ensure that the rest of your gear stays safe from the rain you may want to look into waterproof backpacks and dry bags.
How do you bivy in the rain?
Bivy sacks will protect you from the rain once you are sealed inside of them, but they can be tricky to get in and out of when it is raining. Ideally, you want to get inside of your bivy as quickly as possible and seal it up as fast as you can.
When backpacking you will want to remove your raingear as you climb into or once you are inside the bivy. You’ll want to stuff your wet raingear into a corner of the bivy so that it doesn’t soak through your clothes or sleeping bag. Upon exiting the bivy you will want to put your raingear back on before opening the shelter.
During an emergency, you will likely be better off keeping your rain gear on until help arrives or you can move onward. The bivy will collect condensation from your breath and the wet rain gear, but you will be sheltered from the cold rain outside.
Other Bivy Sacks We Reviewed
We looked at 20 other bivy sacks and bags. Even though they didn’t make our five best bivy sack list, they’re the best of the rest and each is still a great option for minimalist backpacking excursions and emergency shelter. The information you’ll need to compare each one is included with the listing.
Backpacking Bivy Sacks
The Aqua Quest Mummy Bag is a simple, lightweight mummy bag-shaped bivy sack that wraps around your sleeping bag to make it warmer and waterproof. It features zippers on both sides of the sack to easily get in and out of it, and it has a hood with a drawstring enclosure that enables you to wrap up tightly during bad weather and ventilate when able.
- 70D ripstop fabric
- Weighs 1.26 pounds
- Two-year warranty
The well-insulated Leoie Outdoor Bivy Sack is stuff with 1500g of white duck down at 650 fill power for an ultra-plush and ultra-warm sleeping experience. The exterior nylon has a camouflage design that is both breathable and waterproof. This is a great all-in-one sleeping bag and bivy.
- 320T crimped nylon surface
- Filled with 1500g white duck down
- Open-all zipper
The Mammut Bivouac Bag has a time-tested design that features a durable and waterproof nylon bottom and a breathable membrane on top. Though the top isn’t completely waterproof, it is water-resistant and allows water vapor to escape the bag so that you do not build up tremendous amounts of condensation while you sleep.
- Waterproof nylon bottom, breathable membrane top
- Integrated stuff sack
- Drawstring enclosure
Much like the aforementioned Mammut bag, this MSR E-Bivy has a waterproof bottom and a water-resistant, breathable top. The bottom has been coated in a proprietary Xtreme Shield DWR coating, and the top has been coated in silicone that blocks wind, dew, and light precipitation.
- Xtreme Shield-coated floor
- Weighs 7 ounces
- Three-year warranty
The Outdoor Research Alpine Bivy is a comprehensive tent-replacement system that utilizes two poles and a number of guy lines to expand its size for increase comfort and room within the bivy. The GORE-TEX fabric lets moist air escape the bivy while preventing water from permeating in from the outside.
- Made of GORE-TEX
- Pole and guy line structure
- Zippered foot vent
Featuring four zipper sliders, a mesh window, and an adjustable hood visor, the Slumberjack Contour Bivy is a luxurious and practical bivy. The visor flap can cover the mesh window for weather protection, or be left open for ventilation. The four zipper sliders can also be used to create vent openings along the length of the bivy.
- 40D nylon fabric
- Adjustable hood visor and mesh window
- Four zipper slides
The SnugPak Bivvi Bag can double as either a backpacking sleeping bag cover or as an ultralight emergency bivy sack. It has a mummy shape and is entirely made from waterproof and breathable Paratax dry fabric. The hood has a cord that can be used to close the bag for the best protection.
- Paratax dry fabric
- Mummy shape
- Weighs 11 ounces
Constructed with the same Paratax day fabric as its sibling product, the SnugPak Special Forces Bivy stands apart due to its wide foot box and center zipper. This bivy is roomier and easier to get in and out of than its counterpart.
- Paratax dry fabric
- Zippered center with storm flap
- Weighs 12 ounces
Emergency Bivy Sacks
There are many emergency bivy sacks that list identical or similar features as one another, but the Go Time Gear Life Bivy has a refined design made from quality materials that makes it one of the better options on the market. The emergency whistle and versatile paracord are great extras to have in the event of an emergency.
- Reflects 90% of body heat
- 120-decibel emergency whistle included
- 26um mylar design weighs 4.1 ounces
So compact that it can fit in the palm of your hand when packed away, the IntegrityWorksUSA Emergency Bivy is an excellent emergency piece of kit that you can store away in your vehicle or backpack and forget about until the day you need it. It unfolds to a large bag that can fit above average-sized adults.
- 26um polyethylene mylar
- Fits adults up to 6’4″ tall
- Carabiner and whistle included
Extra thick and extra large, the Outdoor Designs USA Bivy Sack is big enough to fit a large adult or two average-sized adults. It is made from a mylar polyester material that remains extremely lightweight at only 4.2 ounces. A 120-decibel emergency whistle is included.
- XL size is seven feet long and three feet wide
- Reflects 90% of body heat
- Polyester construction
The Outdoor Research Helium is a durable, high-quality emergency bivy sack that weighs 9.6 ounces and packs down to the size of a beer can. It is completely waterproof with seam-taped edges, yet it is also breathable like a backpacking bivy. It is 84 inches long and 36 inches wide. This is one emergency bivy that can be used many times over.
- Pertex Shield+ construction
- Drawcord enclosure
- Weighs 9.6 ounces
The SE Survivors Bivy is an emergency bivy through and through, but it has been designed with a thicker than typical 40um tear-resistant material that the company claims is reusable. Most emergency bivys won’t last beyond a single use or two, but this one can. it also reflects a class-leading 95% of your body heat back to you.
- Aluminized PE interior
- Tear-resistant and reusable 40um thickness
- Reflects 95% of body heat
The Survive Outdoors Longer Emergency Bivvy is one of the lightest emergency bivys we’ve seen, and the company claims that it is constructed with tear-resistant, waterproof materials, making it a reusable bivvy that can also be a staple product for ultralight backpackers.
- Ultralight 3.8-ounce weight
- Quiet, tear-resistant material
- Taped seams
The Vijoly Emergency Bivy Sack is a run of the mill bivy sack that is packed with a bunch of “free” extras. This bivy sack will work as well as most other emergency bivys, but it also comes with an emergency blanket, a 120-decibel whistle, and a PDF survival ebook that’ll teach you how to survive in an outdoor emergency scenario.
- Survival kit features an ebook, emergency blanket, whistle
- Reflects 90% of body heat
- 26um thickness
Budget Bivy Sacks
Ask any long-distance backpacker what makes for the best ground tarp and you’re likely to get Tyvek as a response. The 3F UL Gear Upgrade Bivy Sack has utilized this thru-hiker favorite material in the creation of this unique bivy sack design which is ultra-lightweight, waterproof, breathable, and inexpensive compared to other backpacking bivys. We’re sure it’ll protect your sleeping bag and keep you dry, but the Tyvek material feel may take some getting used to.
- Tyvek construction
- Zipper and drawcord operation
- Five-year warranty
The Bearhead Bivy Sack is an excellent emergency bivy sack option that is available in several colors, including camo. It is made of durable polyester and is super light. Included with the product are a stuff sack, carabiner, and emergency whistle. You’ll get multiple uses out of this one.
- 40um thick polyester
- Weighs 4.9 ounces
- Included emergency whistle and carabiner
Another inexpensive backpacking bivy option, the BK Mummy Bivy Sack is a weatherproof and impressively durable bivy cover for your sleeping bag. It’s made of thick 500D ripstop nylon, yet it only weighs 0.6 pounds.
- Made of 500D ripstop nylon
- Weighs 0.6 pounds
- Zipper and velcro enclosures
the Delmera Thermal Bivy is a simple emergency bivy and nothing more. It’s made out of highly reflective mylar that keeps 90% of your body heat within its confines. It’s lightweight, highly visible, and it’ll help you survive an emergency night out in the cold.
- 26um mylar construction
- Reflects 90% of heat
- Weighs 4.6 ounces
Two adults can fit within the MountainSafe Tactical Bivy. It measures seven feet long by three feet wide and weighs a mere 6.3 ounces. A mylar emergency blanket has been included to further protect you from the elements.
- 26um polyethylene construction
- XL size can fit two adults
- Bonus mylar blanket included