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SOL Escape Pro Bivvy Review

The Survive Outdoors Longer Escape Pro Bivvy is SOL’s highest-end (and most expensive) bivvy sack, made of waterproof-breathable Sympatex Reflexion fabric with an aluminum liner which it claims to reflect 90% of your body heat. This fabric is much different from the mylar bivvies The Survive Outdoors (SOL) offers which completely trap moisture inside them during use. While SOL suggests a multitude of uses for the Escape Pro Bivvy Sack, like a sleeping bag liner or cover to add warmth to your sleeping bag, we found it best suited to the purpose of an emergency bivvy or fast-and-light sleeping bag replacement in mild weather, when coupled with appropriate clothing.

Specs at a Glance

  • Materials: Sympatex Reflexion waterproof-breathable nylon, seam-taped
    Weight: 8.4 ounces (Manufacturer); 9.0 ounces plus 0.2-ounce stuff sack (measured)
  • Dimensions: 84” x 31” (Manufacturer); We measured the dimensions to be:
    84” from footbox seam to the highest point on the hood when flat
    72” (AKA 6’) long from foot box seam to top of the zipper (measured).
    30” wide at top of the zipper (60” inch girth) tapering down to 24” wide (48” inch girth) at the foot.

Use Case Testing Questions

I own and have used SOL’s much less expensive Sol Emergency Bivvy, which is non-breathable and functions as a vapor barrier. My questions upon receiving the Escape Pro Bivvy were:

  1. Is it truly breathable?
  2. Can you sleep in it without getting soaked in your own sweat?
    At what temperatures can the bivvy be used on its own?
  3. Do you need to use a pad with it?
  4. Can it function as a stand-alone piece?
  5. What does it feel like to spend an entire night in?
  6. Would I want to use this in any situation outside of a true emergency?
  7. Is it that much of an improvement over the SOL Emergency Bivvy to justify costing almost 10 times more?
  8. How does it work as a sleeping bag cover?
  9. How does it work as a sleeping bag liner?
The inside of the bivvy is aluminized to reflect your body heat Here you see what the opening looks like with the zipper fully open
The inside of the bivvy is aluminized to reflect your body heat Here you see what the opening looks like with the zipper fully open

Bivvy Design and Construction

The Escape Pro Bivvy is constructed with Sympatex Reflexion nylon which is aluminized on the inside to reflect your heat back to you and orange on the outside. The material has some stretch. All of the seams are sewn and then seam taped on the outside for waterproofing.

The zipper is only 16 inches long to save weight, so you have to wiggle into the bag. The hood is a simple, half-circle which lies flat if you don’t have it cinched, but is less contoured than a shaped hood in use. It cinches around its perimeter with a static cord and a cord lock anchored at the side of your face.

While static cord is more durable than shock cord, I would have preferred shock cord here for a more secure, comfortable and dynamic fit. With the static cord, the more I tightened it, the more it wanted to close in front of my face, as opposed to around my face. As a rotisserie sleeper, I found I had to adjust the alignment of the bag as I moved from side to side, as it twisted instead of moving with me.

The seams are sewn and then externally seam-taped

Testing Scenarios

REI’s Escape Pro Bivvy product listing reads, “On evenings above 50°F, leave your sleeping bag at home and travel ultralight with the Escape Pro.” SOL’s product video says, “On nights warmer than 45 degrees Fahrenheit, lighten your pack and save space by using the Escape Pro as your sleeping bag, wearing light insulation to provide the warmth you need, ideal for ultralight backpack, overnight kayak, and long-distance bikepacking trips.”  The product description also recommends using the bivvy as a sleeping bag cover to add an additional 15 degrees to your sleep system.

Without a ground pad

The first night I used the Escape Pro, the temperature was 66 degrees Fahrenheit. I entered the bivvy wearing shorts and a synthetic t-shirt and lay down on the ground without a pad. I quickly felt the cold from the ground on my back, and the fabric on the inside felt cool against my skin. While these were quite mild temperatures, I was too cool to sleep through the night wearing just shorts and a t-shirt inside the bivvy with no ground pad.

Having read the promotional materials which state that the bivvy retains up to 90% of your body heat, I was curious if a ground pad would be needed. It is. I can definitely say that conductive cooling where you touch the ground still happens through the bag. To protect myself from mosquitos, I wore a hat and headnet with the bivvy.

With a ground pad

The second time I used the Escape Pro Bivvy, it was eleven degrees colder. This time, I wore my hiking pants and a fleece pile hoody and used a 3/8” thick closed-cell foam pad underneath the bivvy. This was a much more comfortable scenario, as my long clothing prevented me from feeling the cool fabric and the fleece and foam pad provided enough insulation. The pants and hoody were sufficient to keep me comfortable when I was doing light tasks outside the bivvy, and they kept me comfortable inside the bivvy when I was no longer active.

The slight stretch of the fabric is helpful for side sleepers
The slight stretch of the fabric is helpful for side sleepers

As a sleeping bag

On an early fall camping trip with the family. I packed two quilts–a single person and a two-person, identifying them by size and color and throwing them in the car still in the cotton stow sacks. Or so I thought. Upon arriving at camp that night, I discovered that what I thought was the purple fabric of my multicolor homemade two-person quilt was actually the purple fabric of my winter mummy bag. Home was two hours away so there was no way I could turn around and fetch another bag. In a pinch, I knew we could unzip the mummy bag and share it, although its aggressive taper would have made it a little drafty for two.

But I had the Escape Pro Bivvy with me, and that ended up being my sleeping bag for the night. The forecast was for 50 degrees overnight with lots of wind, and that proved to be accurate. I used the Escape Pro on a summer-weight inflatable pad, again wearing hiking pants and a fleece pile hoody, and was inside a tent. I slept as well as I usually do using a ground system (as opposed to my deep-sleep hammock system). It wasn’t fluffy and cozy like a down quilt, and I experienced some twisting of the bag like I previously described, but I was sufficiently warm and thus able to sleep.
In each of my testing scenarios, I found no condensation inside the bivvy, although it did sometimes feel a little clammy–like sleeping in a waterproof-breathable rain jacket.

The Sympatex really did seem to have good breathability in the conditions in which it was tested, which didn’t include high-humidity nights. I would expect there to be situations in which the clamminess would become condensation, but not nearly to the extent that you’d find using a non-breathable mylar bag.

The Escape Pro Bivvy packs up to slightly larger than a Nalgene bottle
The Escape Pro Bivvy packs up to slightly larger than a Nalgene bottle

As a sleeping bag cover or liner

Using the Escape Pro Bivvy as a sleeping bag cover or liner are two suggested uses in the product materials, but I found it to not do either of them well.

  • As a liner, it does add warmth, but it also removes all of the coziness of slipping into a comfy, fluffy sleeping bag.
  • As a sleeping bag cover, the Escape Pro Bivvy is way too constricting. I’m only 5’4” with a 30” waist, but when I put a thin, 20” wide Thermarest Prolite and a 30*F quilt inside, I felt extremely claustrophobic, like I was pinned on my back.


The SOL Escape Pro Bivvy Sack box reads: “Perfect for all conditions,” but I found a relatively narrow set of ideal uses for it in my testing, as follows:

Best Use:

  • As an emergency bivy bag with a sleeping pad, it is reusable unlike less expensive emergency blankets
  • As a sleeping bag, it is a viable option for ultralight backpacking or adventure racing in summer, also with a sleeping pad

Less Optimal Use:

  • As a sleeping bag liner, it’s a lot less comfortable than the inside of your sleeping bag
  • As a sleeping bag cover, it’s too narrow and claustrophobic

Disclosure: SOL provided the author with a sample bivy for this review.

SectionHiker is reader-supported. We only make money if you purchase a product through our affiliate links. Help us continue to test and write unsponsored and independent gear reviews, beginner FAQs, and free hiking guides.

About the author

Greg Pehrson is an ultralight backpacker who was bitten hard by the MYOG (make-your-own-gear) bug. He repairs, tinkers, and builds gear, often seeking to upcycle throwaway items or repurpose things from outside the backpacking world.


  1. You answered about all the questions I would have for this bivvy. What is the difference between the Escape Pro Bivvy and the Escape Bivvy? Which looks to be about the same other that there is a big price difference. The Pro is not listed on their website

    • I have the non pro version of the SOL Escape Bivy and tested it in just below freezing temperatures in 3 different ways at 8000 ft elevation on top of compacted snow under a pyramid tarp on a 2 night solo backcountry ski venture in the Wasatch mountains in northern Utah where I live. First use was as a ground cloth under my Xtherm mattress which worked fine. But, I was chilly from convection from a breeze getting inside my Revelation 30 degree F quilt when I turned while sleeping even though I was using the quilt straps to pad. Second was as a liner inside the quilt. The bivy felt clammy as a liner but eliminated the convection. Third use was as a quilt cover. There’s not enough room to place mattress and quilt and me inside without being constricted and compressing the down quilt which reduces the quilts ability to trap body heat. However when I placed just the quilt inside the bivy on top of the Xtherm mattress and crawled inside, it worked fantastic to keep me warm by eliminating the convection from breezes and giving me plenty of room for my quilt to loft and trap my body heat. I slept comfortable and noticed that it did add R-value to the sleep system. In the morning, I found no dampness inside the bivy or the entire quilt. There was some frost on top of the bivy and frost on the inside walls of the pyramid tarp. I weigh 150 lbs and am 5’11”. So, I will continue to use the regular Sol Escape Bivy as a cover for my Revelation 30 degree F down quilt without my mattress inside the bivy when I expect weather that is pushing the quilt’s ratings whether that be cold temps, spindrift snow, or wet conditions.

    • The PRO has the external side of the seams taped.

  2. The big takeaway for me from this review is that an emergency bivy sack is worthless if you don’t carry an insulated sleeping pad (because the cold ground will suck all the heat out of you.)

    • I have the non-pro version (doesn’t stretch) it only breathes vapor…. if you sweat liquid it’s gonna be with you the rest of the night. With wool socks, nylon running pants and a hooded fleece I’m really comfortable on a leaf bed under a poncho tarp with no pad down to 39*F & could go colder with more clothes & a three log “long fire” it absolutely makes a “bushcraft bed” comfortable enough for normal people who aren’t into sleeping with ants, spiders, etc. crawling all over you.

    • Try a “leaf bed” some time build a box 30” x your height + 6” out of old logs no need to cut just let one end stick out pile leaves a foot thick, stomp it down till to your personal firmness add another inch or two and sweet dreams. Takes 20 minutes. R value seems like 3-4 as good as a thermarest and almost as crinkly

    • I find the non pro version of this bivvy has lots of uses. But to your comment; as the name implies, an *emergency* bivvy is not worthless. In an emergency you will be cold. Possibly unbearably cold,, especially on the ground, but you will be alive. will certainly not be comfortable and you definitely will not spend the night horizontal on the ground due to limiting conduction. You would be in the emergency position, shivering unbearably, keeping you awake, but again you will be alive. Even if you could sleep, sleeping is obviously not recommended in that situation. But back to its awesome uses; Ive found the bivvy works amazing by itself with long underwear on any of my fast and light missions summer missions down to 45 like the others have said. That with an 8oz ultralight tarp and 2oz poly ground sheet and pad is the only thing you need even in most rain and storm conditions. The bivvy prevents ground splashback and whatever horizontal rain gets thru the tarp sides. In most situations my tarp isn’t even pitched on most clear nights, for occasional sprinkles and scattered rain it’s water proof,(not the zippers this) so I just lay my tarp nearby or on my head if it’s might sprinkle. This speeds setup and takedown of camp significantly. Not to mention using this saves space and lightens load as the bivvy doubles as my daypack daytime emergency bivvy, doubles as my sleeping bag, and doubles as a waterproof bivvy cover. So this Swiss Army knife allows me to get rid of several other options and still have so much versatility. If the weather drops colder this works great as a non emergency liner in your sleeping bag ,where it may not be soft to the touch, but you are not waking up wet from condensation and now have another comfortable 15 degree range to your options just by bringing one emergency bivvy. Also like others mentioned if you don’t compress your bag this can be a great cover, but depends on body size. So many uses for $55 for the regular escape . I’m literally surprised more people don’t use it at this price with so many uses. People are always complaining it doesn’t do one thing well. In my case it does a lot of things reasonably well, and the trade offs are so much better than packing a true waterproof bivvy , or separate emergency blankets, or separate summer bag.

  3. I use mine as a cover on a 1 lb down bag. Makes for an ultra light sleep system and together with a silnylon tarp protects my bag from rain. Summer use only though, and Winter is coming. Going to have up my game!

  4. The claim that these bivvy sacks “reflect 90% of your body heat” is quite misleading. They do reflect your radiant heat. However, radiant heat only represents a very tiny fraction of your heat loss. As noted in the article and other comments, you lose much more heat via conduction to to the cold ground. Bivvy sacks do help a lot with another major heat loss mechanism, which is convection due to wind. Simply providing a windproof barrier is important. And, they do help shield you from cold rain. To the extent that they keep you drier, you will stay warmer.

    Bottom line is that these bags are helpful in a survival situation, mostly by providing shelter from the wind and rain. However the 90% heat reflection claim is mostly irrelevant hype.

    • We actually lose about 65% of our body heat through radiation, which is incredibly significant. Radiant reflectors like these work very efficiently but typically at an expense of increasing evaporative heat loss through sweat and condensation (one reason why you don’t see these in more clothes and sleeping quilts/bag). Radiant heat loss is also reduced through wearing thicker insulation, but again, not as efficiently as a radiant reflector. Bags/clothes are simply better at allowing breathability and, thus, reducing evaporative cooling. Yes, conductive heat loss does increase the higher % of your body surface is in contact with a denser colder surface which is why laying on one’s side or, even better, in the HELP position with padding under your butt will keep your warmer than laying on your back in one of these.

    • Excellent. Right ON. I, too, am 5’3″ & weigh 105# & it is too small for MEeee, my sleeping Bag, & my XLite Thermarest NeoAir Air mattress. I have to put my mattress on the ground & then ONLY MEeee & my sleeping bag fit inside the Bivvy.

  5. I found that a cheap $5 space blanket laid on my tent floor reflection side up with my air pad and quilt on top keeps me quite comfortable. If I’m still cold I just pull half of the blanket over me like a taco shell. I leave the blanket in the tent and just roll it up to reuse.

  6. I use this in my 24 hour pack for Search and Rescue. It works great for that purpose with a 3/4 length foam pad. What limits the versatility for me is the size. At 6’2″ it’s long enough but in just a t-shirt it stretches tight across my chest and shoulders. There’s no way I can layer up and definitely no way I can add even a an ultralight liner bag.

    If SOL made a wider version of this bag it would be perfect for my purposes. As it stands, i’m left looking for other options.

  7. I’m only 5’10” and choose not to use this piece, for the same reason. Would LOVE to see them make a bigger version.

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