Rating

Versatility: 5

Size/Weight: 10

Features: 9

Construction: 9

Sleep Quality: 6

OVERALL: 7.8

Practically as light as air.

At a mere 1lb 4oz/ 600g, the Therm-a-Rest Hyperion is INSANELY light for a sleeping bag of this quality. It's been specifically engineered to be light weight so it's perfect for longer hikes - but keep in mind that does mean some compromises. It's not as warm as others, has quite a snug fit, a half-length zipper and a reasonably hefty price tag - but if you're looking for something immensely packable, this is the one.

Best For: Long hiking trips

Pros: Extremely lightweight, high quality construction.

Cons: Tight fitting, not as warm as others.

Verdict: An ideal sleeping bag for long backpacking trips.

Skip ahead to First Impressions, Sleeping Experience, Features Analysis, Construction and Durability, or the Final Verdict, check out how the Therm-a-Rest Hyperion 20 compares to others in our list of the Top 5 Sleeping Bags.

Specs:

Packed Size: 6 x 8 in/ 15.24 x 20.32 cm

Weight: 1.4 lbs/ 22 ounces

Fill: Nikwax goose down

Approx Price: $939.95

We took this 20-degree mummy sleeping bag out with the expectation of having a lightweight and small pack size - triple tick.

The Therm-a-Rest Hyperion has a  900-fill Nikwax Hydrophobic Down that absorbs 90% less water, SynergyLink connectors for versatility to integrate the bag with a mattress, zoned insulation, and of course, its 20-ounce weight that packs down easily to 6 x 8 inches.

From the outset, clearly an ideal bag for multi-day hikes in fairly decent weather conditions.

To reduce its weight, this bag uses zoned insulation that’s supposed to distribute the heat around the bag by 70% fill on the top and sides and 30% on the back. Unfortunately, this does limit its warmth capacity, and we found it wasn’t great at insulating from the cold ground, even with what we knew to be a great sleeping mat underneath it.

It does have a comfortable nylon outer, but again in an effort to minimise weight it’s also a little tight and we found it harder to move around in than others in our sleeping bag reviews.

There’s a bunch of interesting features that we find significantly distinct on the Hyperion. Its materials and precise design allow for packability with more compressible fabric, without putting in much effort when cinching the bag straps.

We like the versatility of the bag in that it offers optional mattress integration, and our experience with Therm-A-Rest sleeping mats is that they are very good quality so we’d happily integrate. The snag-free zipper with draft tube and adjustable hood were functional and the least of our concerns - on the whole a great range of features.

Therm-A-Rest has been around a while and they know how to build a sleeping bag. For the price, the construction is of a quality you’d expect, and the materials are of a durable enough standard that they should last well over time.

If it had more ability to retain heat and was more spacious, this would be one of the best sleeping bags on the market. Its selling point is definitely its light weight and packability. You can take this to long backpacking trips and jump from one place to another without weight issues and packing inconvenience. For fair weather hiking, this is an excellent choice.

Why not visit our list of the Top 5 Sleeping Bags of 2024 to see how the Therm-a-Rest Hyperion 20 compares?

Water & Outdoors reviews are written by our staff writers, who combined have over fifty years of experience on the water and outdoors. We may earn commissions if you choose to buy through a link you’ve clicked on our website, however this does not influence our reviews. For more information, please see our Editorial Policies.