I’ve used the Therm-a-Rest Hyperion 32 extensively over the past few months, including in nighttime temperatures down to 32°F.
Although it’s far from the best sleeping bag for survival, it’s a solid option for anyone looking for an extremely lightweight sleeping bag that packs down very small.
Because we focus on survivalism and prepping here at Survival World, this review of the Hyperion 32 Sleeping Bag is focused on its uses in long-term wilderness survival situations as part of a go-bag or at a bug-out location.
That said, I will also briefly touch on my opinion of this Therm-a-Rest sleeping bag for normal camping and backpacking uses.
Here’s what you need to know if you’re considering adding the Therm-a-Rest Hyperion 32 Sleeping Bag to your pack.
Quick Thoughts on Hyperion 32 Sleeping Bag
Immediately noticeable about the Hyperion 32 is just how lightweight and compact it is.
This sleeping bag is seriously lightweight at just 16 ounces for the regular version (the long is just 18 ounces while the short is 15 ounces).
Not only that, but it packs down very small thanks to the included compression pack. Toss this sleeping bag in your backpack and it won’t take up much room or weigh you down.
Honestly, like most ultralight sleeping bags, the Therm-a-Rest Hyperion doesn’t feel all that durable right out of the box. I was a little worried it wasn’t going to hold up well to the wear and tear of camping.
But my first outing with the bag made those worries go away. Although every component of this sleeping bag is designed with reducing weight in mind, they’re all incredibly high-quality and should last for a long time without damage.
As a mummy-style sleeping bag, it’s worth noting that the Hyperion 32 is narrow, especially as it tapers down at the feet. In fact, it boasts one of the narrowest footboxes I’ve used in a backpacking sleeping bag (much narrower than my current go-to sleeping bag).
The narrow footbox slightly reduces comfort, although I still found the bag to be quite comfortable, even on week-long outings.
Other features I want to mention here are the built-in hood to improve insulation and the removable sleeping pad attachment system to keep you from rolling off your pad during the night.
As far as warmth goes, Therm-a-Rest has given the Hyperion 32 a 32°F minimum temperature rating.
After using the sleeping bag at the tail end of winter here in Washington State, there’s no way I’d want to use it alone in temperatures around 32°F.
In fact, I was even a little chilly using this sleeping bag on nights that hovered around 45°F, but combining it with long underwear did keep me warm enough.
I probably won’t use this sleeping bag on any nights under about 50°F in the future. This means that the Hyperion 32 isn’t a true three-season sleeping bag. I’d argue it’s best for the summertime as well as the last month of spring and the first month of fall.
Pros and Cons of the Therm-a-Rest Hyperion 32
The Therm-a-Rest Hyperion 32 is undoubtedly a quality sleeping bag. But, like all outdoor gear, it has its pros and cons.
What I Like About the Hyperion 32 Sleeping Bag
A few of the things I like most about this survival sleeping bag include:
- Compact – This sleeping bag packs down super small to just 2.8 liters for easy storage in your rucksack or assault pack.
- Lightweight – The regular length version of this sleeping bag weighs only 1 pound which is one of this bag’s main selling points.
- Comfortable – I personally found the Hyperion 32 quite comfortable, despite the narrow footbox and short zipper.
- Pad Attachment – I love the pad attachment on the back of this bag. I roll around a lot at night so this helps keep the bag centered on your sleeping pad.
- Built-In Hood – A hooded sleeping bag is always a big benefit for long-term survival since it helps keep in your body heat and sort of acts as a makeshift pillow.
Also worth noting is that this sleeping bag comes with an included compression stuff sack to help further compress it down for easy storage in your backpack.
What I Don’t Like About the Hyperion 32 Sleeping Bag
A few of the things I don’t like about this survival sleeping bag include:
- Narrow – This bag is quite narrow, especially at the footbox. I didn’t find it unduly uncomfortable, although there are much more comfortable options available.
- Not Very Warm – The Hyperion 32 is much colder than most other 32°F sleeping bags.
- Short Zipper – The zipper is noticeably short. It makes getting into and out of the bag slightly difficult, especially in a confined space (like inside of my Snugpak Ionosphere 1-Person Tent).
Another con worth mentioning is price. The Hyperion 32 is very expensive. In my opinion, most campers will be better off selecting a more affordable sleeping bag (especially if your main focus is long-term survival).
Therm-a-Rest Hyperion 32F Sleeping Bag Features & Specs
Here are the most important features and specs for the Hyperion 32 Sleeping Bag:
|Weight: 1 Pound (Regular Length)||Packed Size: 2.8 Liters|
|Temperature Rating: 32F||900-Fill-Power Nikwax|
|Hydrophobic Goose Down||Box Baffled Design|
|Built-In Sleeping Pad Attachments||Built-In Hood|
|Comes w/ Stuff Sack||DWR Shell Fabric|
Visit thermarest.com to learn more about the Hyperion 32 Sleeping Bag’s features and specifications.
Is the Therm-a-Rest Hyperion 32 Sleeping Bag Right for You?
I don’t recommend the Therm-a-Rest Hyperion 32 for long-term survival.
There are much better options available for preppers for both short-term bug-out bags and long-term survival kits.
The main reason I don’t suggest the Hyperion 32 as your survival sleeping bag is because of its temperature rating.
Although it’s rated for temperatures down to 32°F, it really is best suited for temperatures 45°F (at a minimum) and above.
Personally, I believe that a survival sleeping bag should be able to keep you warm in temperatures at least down to freezing – and this one can’t do that.
With that said, the Hyperion 32 does boast an excellent weight to warmth ratio. The bag is surprisingly warm for just how lightweight it is.
If you have money to spare on an expensive summer-only sleeping bag, then this one might just be for you. The same goes for ultralight backpackers looking for one of the lightest bags on the market.
But, since most of you reading this review are likely preppers, I recommend looking into the alternatives below before pulling the trigger on the Hyperion.
Alternatives to the Therm-a-Rest Hyperion 32
A great way to get a little extra warmth out of the Hyperion 32 is to pair it with a sleeping bag liner.
Although I’ve yet to try this combo out myself, a sleeping bag liner usually adds between 10°F to 15°F to your sleeping bag.
This is probably the best option for ultralight backpackers eyeing this Therm-a-Rest sleeping bag because of its ultralight design who still want to use it in fall and spring.
Another alternative for a similar temperature rating is the Snugpak Jungle Bag.
I’ve recently tested out this sleeping bag myself and been pleasantly surprised. Like the Hyperion 32, the Jungle Bag isn’t designed for cold weather. It’s best suited for temperatures no lower than 45°F, although I’d personally only use it in temperatures above 50°F.
With that in mind, the Snugpak Jungle Bag is a much better sleeping bag for survival because of its incredible durability, built-in bug net for when you can’t sleep in a tent, and antibacterial properties to reduce odor and keep you healthy during long-term use.
In terms of long-term survival, the only area where the Hyperion 32 beats out the Jungle Bag is in terms of weight and packed size.
The final alternative I’ll mention is the Kelty Cosmic 20 Sleeping Bag. It’s slightly more spacious than the Hyperion 32, much warmer, and has a much longer zipper which makes entering and exiting the bag that much easier.
Once again, the main downside to the Kelty Cosmic 20 compared to the Therm-a-Rest Hyperion 32 is its weight. The Cosmic 20 weighs in at 2 pounds 15 ounces (for the long version) versus the Hyperion 32’s 1 pound 2 ounces (for the long version).
Of course, the best survival sleeping bag for you depends on your personal needs, location and climate, and type of shelter (tent, bivy, hammock, etc) you’ll be using.
What’s the Verdict?
There’s no denying that the Therm-a-Rest Hyperion 32F is a high-quality ultralight sleeping bag.
However, it has limited uses (due to its poorer than expected temperature rating), especially in a long-term survival scenario.
Not only do I suggest looking for a slightly warmer sleeping bag, but I also think most preppers will be perfectly fine with a much more affordable bag. You’ll be able to find one for at least half the price of the Hyperion 32.
That said, I want to reiterate that the Therm-a-Rest Hyperion is a fantastic ultralight bag for summer backpacking trips or for ultralight backpackers who don’t mind chilly nights.