Flame™ Ultralight Women's Sleeping Bag

Five VERSIONS for performance in any season

$229.00 – $549.00

What Is This

Sleeping Bag Temperature Ratings Explained

The EN Rating scale is a scientific test to determine the warmth of a sleeping bag. The test produces a Lower rating (for male sleepers) and a Comfort rating (for female sleepers). Both are listed in the features table on the product page.

A unisex sleeping bag with a Lower limit of 23ºF means a man should be comfortable down to air temperatures of 23ºF. The same bag will also have a Comfort limit, in the realm of 32°F, so a woman would be comfortable down to an air temperature of 32ºF. These ratings require a sleeping mat with an R-Value appropriate for expected ground temperatures – without this, the sleeping bag itself is unlikely to keep the sleeper warm enough.

A variety of factors impact sleeping bag warmth - the above temperatures are merely guidelines, not guarantees. It’s important to think of a sleeping bag, an appropriately insulating sleeping pad and a liner as a sleep system. For example - if you plan on sleeping in nighttime air temperatures of 27ºF / -3°C, choose a bag with a gender-appropriate rating of 23°F / -5°C, plus a sleeping mat with an R-Value of 2.5 to 3, and consider a Reactor thermal liner.


The Flame™ Ultralight Women's Sleeping Bag Series spans everything from an ultralight down-filled liner to a mid-winter fast-and-light sleeping bag. Each model uses premium materials and no-frills design to provide cutting-edge performance for the designed end-use.

The women’s specific fit is narrower at the shoulder and wider at the hip, and features extra down compared to the unisex Spark models.

Is this women's down sleeping bag…?

  • Suitable for cooler temperatures? Yes. You would want the Flame 15°F or possibly the 25°F – either bag will work in late Fall, the 15°F will take you down to early winter temperatures when paired with an adequately insulating sleeping mat.

  • Really suitable as a sleeping bag liner? Yes. You could use the Flame 55°F, or even the Flame 48°F or 35°F to boost the performance of a bag for cold-weather use. Adding one of these to a 20°F / -5°C sleeping bag might make more sense than buying a “0°F / -20°C” sleeping bag for occasional winter use.

  • Able to be zipped to another sleeping bag? No. Even though the 25°F and 15°F have full-length side zippers, they are not designed to be coupled to a sleeping bag with a left zipper.

Read up on the factors which define and affect down quality, and what they mean for you as an end user HERE


Best Use

  • Ultralight Backpacking, Sleeping Bag Liner


  • Sleeping Bag Liner: 55°F (comfort range 55°F to 75°F)
  • Warm Weather: 48°F (comfort range 48° to 68°F)
  • 2 Season: 35°F (comfort range 35°F to 67°F)
  • 2.5 Season: 25°F (comfort range 25°F to 62°F)
  • 3 Season: 15°F (comfort range 15°F to 60°F)

Designed to keep women warm with

  • Down chambers filled using body-mapping to maximize warmth for a woman’s physiology
  • A wider shape between hips and knees to allow you to sleep in a natural position without compressing the down insulation and creating cold spots. 
  • Shorter overall length and narrower girth in shoulders to reduce dead space and increase thermal efficiency


  • ULTRA-DRY Down 850+ Loft 90% Down Cluster Premium Goose Down certified Responsible Down Standard (RDS)
  • 10D shell and 7D liner materials help to achieve the incredible lightweight and compact packed size
  • Includes lightweight Ultra-Sil™ compression bag and storage cell
  • Zipper-length trimmed for gram-saving performance
    • 55°F, 48°F, and 35°F have 1/3-length zippers
    • 25°F and 15°F have full-length side zippers
  • Baffle construction
    • 55°F and 48°F have sewn-through construction.
    • 35°F has baffles in the torso and sewn through in the leg area.
    • 25°F and 15°F are fully baffled.