2026 edition Outdoor Research Helium Bivy
Hey everyone, wanted to drop a quick review of the Outdoor Research Helium Bivy 2026 from a 5’7" woman’s perspective, because my last trip was a massive learning experience.
First off, the specs on this thing are awesome. It weighs next to nothing at 448 grams (15.8 oz) and packs down incredibly compact to about 32 x 12 cm. Setting it up is a breeze and takes maybe two minutes. I was also really surprised by how roomy it is inside. I had plenty of space to store my extra gear at my feet and sides. Plus, the single arch pole keeps the fabric completely off your face, so with that and the built-in mosquito net, it doesn't feel claustrophobic at all.
But here is where things went sideways. I took it up into the alpine in sub-zero temperatures. Because it was freezing, I zipped the main shell completely closed. About an hour in—fortunately, I was still awake reading—I literally started to suffocate. The Pertex fabric just doesn’t let enough fresh air pass through when it's sealed, completely cutting off my oxygen.
To breathe, I had no choice but to undo the main zip and leave the mosquito net partially open. This immediately let the sub-zero alpine air straight into the bivy. To make matters worse, I hadn’t thought about pitching the entry away from the wind, so I was facing right into the freezing air stream. On the bright side, I had the absolute best view of my life. On the downside, I froze, turned around every 20 minutes, woke up my neighbors.
I survived and learned some major lessons for alpine bivy camping:
Never zip the main shell fully closed. You have to leave it cracked for oxygen, no matter how cold it is.
Pitch smart. Find a spot with good wind protection and always position the entrance against the wind flow.
Beef up your sleep system. Since you have to vent freezing air all night to breathe, you need to significantly increase the warmth rating of your sleeping bag or duvet.
If you move often in your sleep, consider buying a different tent.