Outdoor Research Helium Bivy

Top 25 in Bivy Sacks


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Spacious lightweight bivy, waterproof, and breathable…

Rating: rated 4 of 5 stars
Source: bought it new
Price Paid: $148.07


Spacious lightweight bivy, waterproof, and breathable with minimal condensation issues.


  • Small packed size
  • Lightweight
  • Weatherproof


  • Mild condensation issues on clear, cool night
  • Storm flap blocks airflow when not fully closed

I have spent almost two weeks in the Outdoor Research Helium Bivy and found it to be pretty acceptable for my use. I bought it from Massdrop for $148.07, and when received, tried it out on my back lawn without turning off the early morning sprinklers. I slept comfortably all night and did not get wet from the sprinklers, which were on for 20 minutes. 

More recently, I took the bivy on an almost two-week trip to Shasta Trinity National Forest and slept in it almost every night. I was car camping and used it mostly as a bag cover to keep my sleeping pad, pillow, and sleeping bag clean. I would inflate the pad each night, deflate it in the morning, and simply roll up the bivy with everything inside into an old school bedroll. It probably took me less than a minute to set up and break down my sleep system each night and morning, which is exactly what I was going for.

Sometimes I used the bivy with the provided tent pole to keep some room between the bivy material and my sleeping bag and head, and sometimes I did not. One night, I tied the loop over the entry to a tree branch above me. I did not notice a performance difference any which way. The top fabric seemed to breathe very well and I only noticed interior condensation on one occasion (more on that below). 

There is one particular design quirk that seems less than ideal. When the storm flap is closed, there is a clear path from head to toe. However, with the storm flap open in either open air or bug net mode, the storm flap hangs down from the tent pole and effectively blocks air flow from the chest down to the foot box. I have tried a binder clip to hold it up with limited success and am worried about damaging the waterproof fabric on top.

I kept my pad inside the bivy but did not use the bivy's pad straps, nor did I feel after several nights that I needed to do so. I was using a full size Klymit Insulated Static V Ultralight inflatable pad and felt like I had plenty of room. I am 6'1" and 230 pounds. I am a stomach sleeper and had room to sleep with an arm over my head and under my full size pillow, which I also had in the bivy. My arm was still inside the bivy, but off my pad. The bivy would easily accommodate a larger pad.

I did not feel like I could take much gear into the bivy and left my stinky boots outside, as well as some other clothing. There were rain showers one evening before I went to bed, so I put my extra clothing under the bivy to stay dry just in case the showers returned. They did not, and I was comfortable sleeping on my clothes laid flat underneath the bivy. 

I only noticed condensation inside the bivy on one occasion. I was sleeping on a sandy surface with only sparse, low vegetation around. The sky was clear and I believe the temperature got into the low 30s. I do not know what the dew point was. I only noticed a small amount of interior condensation, and I used a synthetic bag (North Face Cat's Meow, long), so it was no problem. There was also frost on the outside of the bivy. It was my last night out, so I simply rolled everything up as usual and aired it out when I got home. I had slept in a wooded area with plenty of tree cover nearby several nights earlier and did not have any interior condensation at that location, but I wanted to stargaze from my sleeping bag on the last night. 

Overall I was pleased with the bivy, but for a small weight penalty of 8 ounces, I am strongly considering purchasing the Miles Gear Uber Bivy for future trips because it is larger and from what I've read has next to zero condensation issues.

The Outdoor Research Helium Bivy is the only bivy that I have ever spent a full night in, and I am happy with its performance. I tried a non-breathable SOL emergency bivy once in my backyard and very quickly got very damp and miserable from my own sweat, so I went inside.

Bottom line on this bivy is that it is fairly spacious for a bivy, it's light, pretty breathable, and waterproof. Not a bad option if you're into bivys. If forced to spend an entire day sheltering inside from rain, I would prefer a tent; however, I don't typically stay inside due to foul weather, so a bivy is no problem for me.


Welcome to Trailspace, Graham! Thanks for sharing your first review with us. If you have some pictures of your OR bivy in use, I'd love to see them in your review.

29 days ago
Jeff Ashford

Good review of the use and limitations of a Bivy, while I carry for more emergency type hikes, the recent trends in lite weight tents and tarps can make more sense if weather is iffy. I have slept in them on occasions but sometimes on top of.

26 days ago

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