In the world of ultralight sleeping bags, there is an array of models that reduce weight through premium down, thin shell materials, and efficient feature sets. One such bag is the Sea to Summit Spark at just 12 ounces with 20-degree rating – that packs down to the size of a Nalgene bottle!

1. The Nemo Tensor Extreme Conditions

If you are an experienced backpacker camping in winter and other cold conditions, the Nemo Tensor Extreme Conditions sleeping pad could be perfect for you. It boasts marginally higher R-value and weighs only two ounces more than its predecessor, Tensor Trail and All-Season models.

What sets the Tensor EC apart is its Apex baffle internal structure. Featuring low-stretch die-cut trusses to provide stability and evenly distribute weight across the pad, which enables free floating layers of Thermal Mirror metalized film insulation with an impressive R-value of 8.5.

Instead of the Mylar baffles commonly found on competing pads, these layers do not weld together, eliminating that potato chip crunch common to insulated air mattresses and creating a more comfortable sleep surface. Furthermore, Tensor EC features fabric with improved puncture resistance and strength properties for increased puncture resistance and strength.

2. The Feathered Friends Flicker 40 UL

Temperature regulation requires multiple ways of configuring a quilt sleeping bag, and the Flicker does just that with its full-length zipper and transformable foot box, enabling sleepers to enclose or open up the quilt as necessary, including an optional down-filled draft collar that can be tightened tightly around their nose and chest area to stop warm air from venting up through their nose and chest area.

Feathered Friends’ 950+ fill power goose down is highly compressible and offers exceptional warmth-to-weight ratio, boasting an ultralight 10 denier Pertex Endurance shell. Their Tanager, Vireo and Classic jackets also offer great warmth-to-weight ratios with their hood and zipper features.

3. The Katabatic Gear Alsek 22F Quilt

Quilts differ from sleeping bags in that they offer multiple sleeping positions and styles; therefore Katabatic Gear provides three quilt options tailored to fastpackers based on their preferred environment and sleeping style.

The Alsek blanket is designed to keep you warm in all temperatures with its cozy draft collar and sturdy draw cord, pad attachment system and ability to open completely for use as a blanket on warmer nights, as well as tighten up when necessary. It can even be cinched and zippered closed when desired!

The Alsek offers excellent overall features for a quilt/sleeping bag hybrid, but suffers from two notable drawbacks – its sewn footbox and lack of hood are its only serious shortcomings. Otherwise, its benefits make it unrivalled among its counterparts; you can even upgrade with an ExpeDRY treatment to protect it from moisture build-up and performance degradation.

4. The Therm-a-Rest Hyperion

The Hyperion is an exceptional ultralight bag for thru-hikers and alpinists, featuring ultralight materials and careful design that allow it to pack down into an unrivalled ultracompact size. Furthermore, its compact compression sack can even help preserve loft post adventure!

Therm-a-Rest has designed this bag using 900-fill down that remains dry and warm 60 times longer in wet environments compared to untreated down. Furthermore, Therm-a-Rest’s Radiant Reflective Heat feature uses special material on its interior surface that reflects body heat back towards sleepers to add extra warmth for warmth during use.

One drawback of the Hyperion mattress bag is that it features a tight-fitting, half-length zipper; this could prove uncomfortable for sleepers with wider shoulders or hips.

5. The Western Mountaineering Versalite

This bag is an ideal solution for climbers looking to stay warm on summit bids, as well as those wanting to minimize pack weight for 3-season backpacking and kayaking adventures. It’s warm enough for through-hikes without becoming overheated while exploring nature in the mountains.

An outstanding feature is its snag-free zipper, with stiff strips sewn on either side to avoid snags when opening or closing it. This small detail can make all the difference in how often cold air enters and your zipper snags when you wake up!

ExtremeLite shell fabric was water-resistant in our light rain test, proving effective. Goose down tends to lose some of its insulation when wet; for this reason, pairing this tent with waterproof tent such as Marmot Col is recommended.