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:
- Is it truly breathable?
- Can you sleep in it without getting soaked in your own sweat?
At what temperatures can the bivvy be used on its own?
- Do you need to use a pad with it?
- Can it function as a stand-alone piece?
- What does it feel like to spend an entire night in?
- Would I want to use this in any situation outside of a true emergency?
- Is it that much of an improvement over the SOL Emergency Bivvy to justify costing almost 10 times more?
- How does it work as a sleeping bag cover?
- How does it work as a sleeping bag liner?
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.
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.
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.
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:
- 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.