I'm a big fan of this little bivvy. It is about 2/3 the size of a soda can and only weighs a few ounes, which means it's not much bigger and doesn't weight much more than a regular emergency blanket. But, it covers your entire body and head and therefore provides a lot more protection than a regular emergency blanket. I personally own two of these. I always keep one in my day pack which I use for everything ranging from short casual hikes to hiking rim-to-rim at the Grand Canyon. I also keep one in my emergency kit in my car. I've since purchased at least a half-dozen of these to give as gifts to my fellow hiker and disaster preparedness friends.

I'm also a fan of the Adventure Medical Kits Survive Outdoors Longer Escape, Bivvy Breathable Blanket (I have bought two of these for our two bug-out-bags for emergencies that might happen while we are home). But, it costs more and takes up about 6 times the space. And, while I would recommend this one for overnight hikes in areas with nice weather, more serious emergencies, or longer-term use, it is not suitable for a day pack given its size and weight, or cost effective if you need more than one or two.

But, this little bivvy has a high cost/benefit ratio for those sorts of things. It is a small, light weight, inexpensive, and worthwhile addition to any day pack or emergency kit.

I used this while backpacking when the weather dropped into the low 40's. I learned a lesson about having the right thermal gear. I'm a hot sleeper and I sleep with the window cracked in the winter all the time but there is a difference between being in my bed and being outside on the ground. My inflatable sleeping pad didn't have great insulation and I found I was losing my body heat into the ground. I wasn't in danger of freezing or anything like that but it was midnight and I just wanted to get some sleep so I put this over my sleeping bag and feel back to sleep. I think if I had a better sleeping pad I woudn't of needed to take this out.

As others have pointed out this product ends up getting wet from condensation. When I woke up in the morning I found my down sleeping bag was all wet asking with the inside sides of the SOL emergency blanket. I had to let the sleeping bag dry out before putting it back up. I don't consider this a fault of the product though - the materials perform as I would expect.

This is one of those things that your emergency kit - whether in your car, for camping, or backpacking - should not be without. It is lightweight but effective and packs down incredibly small, about the size of a 4 fluid ounce bottle. The bivvy sack comes in it's own small bag with a drawstring and there is still room inside to include additional small emergency supplies. It is so light and so inexpensive, there really isn't a good reason not to have one of these as an emergency backup shelter. It is especially good for dayhikes, where you don't want to pack a lot; there is ALWAYS a possibility of a dayhike going wrong when you hike far and are remote (getting lost or injured) and if you absolutely have to spend the night when you didn't expect to, you'll be glad you tossed this little guy in the pack.

While the material is reasonably strong, it can still be torn by shoes, keys, and other sharp objects, greatly reducing its effectiveness as a survival shelter. This is something that you have to climb into and there is only room for one, so take that into account if you are seeking to provide emergency shelter provisions for more than one. I personally feel this is superior to other emergency blankets as it is basically a tube rather than a sheet, and the material seems more durable than others I have looked at.

I was surprised by how small and light this bivvy roll was when it arrived (I ordered two), and I immediately opened it up and tried it out. It is roomy enough for a 6' tall 200# man, and you could probably fit two in here in a dire pinch. I pack these with me, essentially as emergency sleeping bags/shelters on all outings, since they're so small and light. You would be VERY glad for this if you were SOL without a traditional blanket or had to remain over night in the woods unexpectedly. This does not replace a tent and sleeping bag for sure, but it will probably keep you from dying of exposure in pretty low temperatures, and you may have this when you forget to pack a safari tent when your car breaks down in the snow.

In a wilderness setting, I would insulate under this bag with whatever brush I could find and then around the bag with dried leaves and then wrap up in a second bag, which I also bring along, and that would be VERY effective to keep you warm and dry at night. Ideally, you would want to get under cover of shelter and off the ground. Still, this bag would help cut the wind and at least keep the wind from evaporating all of the moisture from your skin and chilling you further. It might even help if trapped on a ski lift for a week with wolves roaming below, just don't take your glove off and freeze your hand to the safety bar. Even in warm weather, this would be helpful for someone going into shock, if their core temperature began falling.

This product is far superior to an emergency blanket, because if you've ever had to use one, you know it's like covering yourself with a 4' square of tissue paper in gale force winds. Drafts get under the blanket and it's not nearly as water resistant since you are exposed where your undoubtedly poor wrap job "seals" around you.

These would also work wonders to prevent hypothermia on a hiking in the cold, if someone fell into water. You could get into this bag skin to skin with someone to save their life, or just get frisky. You could use this bag to: carry light important items, like food; collect water; signal to rescuers; cut open to create a heat reflector for a fire (why it's good to bring a sucky emergency blanket along also); create a water still or rain collector; reflect heat AWAY from you when you need shade shelter in open sun; line your pack and place clothing for some water proofing when crossing a stream/river; cover an amputation stump to prevent blood loss or seal a sucking chest wound; create a cheesy Halloween costume as the orange ghost; or make a wind sock in your yard.

5 stars for value, good strong material for what it is, design/roominess, superiority to an emergency blanket, re-useability, extra space in stuff sack for quick roll job or extra items, and life saving potential for low cost/space/weight.

We were 4 miles up the mountain and 5 hours into the freezing rain hike when my co-leader broke her leg. We self-evacuated for as long as she could stand but then it was clear we needed to get her warmer, drier, and rested. Enter SOL Emergency Bivvy! I sent two hikers ahead to "set up camp" and by the time we got there they had a huge fire burning, the sleeping bag and insulated pad tucked in the bivvy and waiting for our hobbling leader. We got her inside the bivvy with her splint, the sleeping bag, pad, and the 3 coats we had on her. It was perfect, she was toasty in minutes. And even as the splint hiking pole tips were straining against the edges, it didn't rip. If anything we had to watch condensation buildup. Now every single hiker with us is buying one too. It's just too small to not have on you at all times. I'll add the video of the event later but I can't give a higher rating for any product. Only reason I have to buy another is the SAR team sliced her out to save time.