Shelter ยท Gear Review
Emergency bivvies. A blanket you can climb into.
A bivvy is a light sack you climb into. It does what an emergency blanket does, but wind cannot get under it and you do not have to hold it closed. The SOL Emergency Bivvy is our pick for a day pack. If you might spend a whole night in one, the breathable SOL Escape is worth its higher price, because condensation is what makes a long night in a plain bivvy miserable.
Top pick
SOL Emergency Bivvy
Typical price
About $25 to $29
Readiness tier
Survive
At a glance: SOL Emergency Bivvy
Strengths
- It closes around you, so wind cannot get underneath the way it does with a blanket.
- It weighs 3.8 ounces and packs about as small as a soda can.
- SOL lists sealed seams, a whistle, and a tinder cord drawstring.
Limitations
- It does not breathe, so the inside gets damp over a long night.
- Some critical reviewers find the film no tougher than cheaper generic bags.
- It is a one-person bag with little room for extra layers inside.
By Dan Whelan, founder of New World Survival
Researched from maker specifications, OSHA, CDC, CPSC, and owner reports. See our sources
The field
Sealed or breathable: that is the real choice.
Most emergency bivvies are sealed film bags that hold your heat and your moisture in. A few are made of a breathable fabric that lets some moisture out. Specifications come from each maker or its Amazon listing; we did not test them ourselves.
Not sure a bivvy is what you need? Our emergency shelter handbook compares bivvies with blankets, tube tents, and tarps.
| Bivvy | Best home for it | Size | Weight | Breathable | Maker's heat claim | Typical price |
|---|---|---|---|---|---|---|
| SOL Emergency Bivvy | Day pack, car kit | 84 x 36 in | 3.8 oz | No | 90% | About $25 to $29 |
| Go Time Gear Life Bivy | Car kit, first aid kit | Not listed | 4.1 oz | No | Up to 90% | About $22 |
| SOL Escape Bivvy | Hiking pack, overnight trips | 84 x 31 in | 8.5 oz | Yes | 70% | About $86 |
The heat percentages are each maker's own claims about reflected body heat. We found no independent standard behind them, so we did not rank on them.
Our picks
Light for the pack, breathable for the long night.
Top pick
SOL Emergency Bivvy
An 84 by 36 inch sack that weighs 3.8 ounces and packs about as small as a soda can. SOL lists sealed seams, a whistle, a tinder cord drawstring, and tear-resistant material. (SOL) It is about $25 from SOL and a little more on Amazon, where it carries several hundred ratings averaging 4.7. It wins on a long track record and a maker that publishes its specifications.
Find it on AmazonBudget pick
Go Time Gear Life Bivy
The most-rated bivvy we found on Amazon, with more than 5,000 ratings averaging 4.6, for about $22. It weighs 4.1 ounces, comes in a waterproof stuff sack with a whistle, and is made of 26-micron coated polyethylene. It was sold out on Go Time Gear's own store when we checked. (Go Time Gear) Critical owners describe it as a large space blanket shaped into a bag, which is a fair description of every sealed bivvy.
Find it on AmazonBreathable pick
SOL Escape Bivvy
Made of a spunbonded fabric with a metalized coating that SOL says cuts condensation and will not shred if punctured. It reflects less heat by SOL's own numbers, 70 percent, and weighs 8.5 ounces, but you stay drier through a long night, and SOL says it lasts through multiple trips, with a two-year warranty. (SOL) About $86. The current hooded version is new on Amazon, with few ratings so far.
Find it on AmazonAffiliate disclosure: New World Survival earns a small commission on qualifying Amazon purchases at no cost to you. This helps us cover operating costs and keep building new content. We only recommend gear we would put in our own kit. Commission never decides a recommendation.
What owners actually say
Warm enough to sweat in. Then damp.
These patterns come from Amazon owner reviews, including the critical ones, read November 4, 2026. A pattern means many independent owners said it.
Condensation is the complaint
Owners who spent hours in a sealed bivvy, including some who used one indoors during a winter power outage, describe it holding heat and then growing damp inside. One said the dampness kept them from ever feeling warm. That is the physics of a sealed bag, not a flaw in one brand.
Thinner than expected
A recurring theme for both sealed picks is that the film feels like a mylar balloon, and that the bag is a space blanket in another shape. Some critical reviewers say a cheaper generic bag feels much the same. Most still keep one in the kit, because it weighs almost nothing.
Small things missing
Individual owners report a missing whistle, or cords that came loose from the stuff sack on first use. Open yours at home, check it, and repack it before it goes into the kit.
The one thing to know
Moisture decides how long you can stay in one.
A sealed bivvy traps the water vapor your body gives off. OSHA notes that wetness, even from sweat, speeds heat loss, and its first aid for someone with hypothermia wraps the head and neck but leaves the face uncovered. (OSHA) In a bivvy, keep your face outside the bag so your breath's moisture stays out, open the top whenever you can, and change out of wet clothing before you climb in. Wear your warm layers inside and put something between you and the ground.
For a short wait, a sealed bivvy is fine. For a whole night, a breathable bivvy keeps you drier, and a sealed bivvy works better pulled loosely over a sleeping bag or warm layers than as your only cover.
Never bring a fuel-burning heater or lantern into a small shelter. The Consumer Product Safety Commission says never to use them while sleeping in enclosed areas such as tents, campers, and vehicles, because of carbon monoxide. (CPSC)
A bivvy cannot rewarm someone with hypothermia. CDC lists the warning signs in adults as shivering, exhaustion, confusion, fumbling hands, memory loss, slurred speech, and drowsiness. A body temperature below 95°F needs medical attention right away. If help is not available right away, CDC's steps are to move the person somewhere warm, remove wet clothing, and warm the center of the body first: the chest, neck, head, and groin, with an electric blanket if you have one or skin-to-skin contact under loose, dry layers. Once they begin to warm, keep them dry and wrapped, head and neck included, and get them medical care as soon as possible. Never give alcohol, and give nothing by mouth to someone who is not awake. If the person is unconscious and seems to have no pulse or breathing, handle them gently, get emergency help immediately, and start CPR even if they appear dead. Keep going until they respond or help arrives, and keep warming them while you do. (CDC)
How they fail, and what they cost over time
Sealed ones are single nights. Breathable ones last.
Damp from the inside
The most common failure is not a tear but moisture. Open the top, keep your face out, and dry your clothes and the bag whenever you can.
Punctures underneath
Thin film punctures on sticks and rocks. Clear the ground and lie on a pack or a coat. Tape patches a small hole.
Hard to repack
Once out of its sack, a sealed bivvy rarely goes back as small. Replace a used one in your kit and keep the old one as a backup.
The cost
About $15 to $29 for a sealed bivvy, replaced after real use. About $55 to $86 for a breathable one that lasts many trips. SOL lists a 60-day guarantee on its sealed bivvies.
What we didn't pick, and who should skip
Close cousins, and better fits for some kits.
SOL Escape Lite
The lighter breathable bivvy, 5.5 ounces and about $55, which SOL also sells as a sleeping bag liner. It was sold out on SOL's store when we checked. A good choice for hikers if you can find it.
SOL Thermal Bivvy
A heavier, more durable sealed bivvy, 8.9 ounces and about $44, which SOL rates as water resistant with an 80 percent heat claim. It sits between our top pick and the Escape without being breathable.
Generic mylar sleeping bags
Single bags from about $15 and four-packs for about $25 fill the listings. Some owners find them much the same as the branded ones. They suit kits for several people; check that each bag is sealed in its own packet.
Skip a bivvy for the car
In a car, an emergency blanket per person plus real warm layers is simpler and cheaper. See our emergency blanket picks.
Skip it for two people
If two people need cover together, a tube tent hung between two trees is roomier. See our emergency tent picks.
Skip it as your sleeping bag
A bivvy adds little insulation of its own. For planned nights out, bring a real sleeping bag and use a bivvy over it.
Where it fits in your readiness
In the day pack, and the bag by the door.
A bivvy belongs in the Survive tier, in a hiking pack or the bag you would take if you had to leave home in a hurry. It earns its place when you are outdoors and help is hours away, and as a warm layer during a long winter outage at home.
Questions people ask
About emergency bivvies.
What is an emergency bivvy?
A lightweight sack you climb into, made of reflective film or fabric. It does the job of an emergency blanket, but it closes around you, so wind cannot get underneath and you do not have to hold it shut.
Why does the inside of my bivvy get wet?
Your body gives off moisture, and a non-breathable bivvy holds it in. Over a long night the inside gets damp, and OSHA notes that wetness, even from sweat, speeds heat loss. Keep your face outside the bag, open the top when you can, or choose a breathable bivvy such as the SOL Escape.
Is a breathable bivvy worth the extra money?
If you might spend a whole night in it, yes. A breathable bivvy lets some moisture out, so you stay drier. It reflects less heat by the maker's own numbers and costs several times as much, so for a car kit or a short wait, a basic bivvy or blanket is enough.
Can I use a bivvy instead of a sleeping bag?
Not as a planned sleep system. A bivvy adds little insulation of its own. It works best over warm clothing or a sleeping bag, where it blocks wind and reflects heat. On its own, it is for the night you did not plan.