Sea to Summit Flame 15 Review

Compare prices at 3 resellers Pros: High-quality down, warm and lofty, light, a top tier product
Cons: Expensive
Manufacturer: Sea to Summit
Our Verdict
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Sea to Summit Flame 15 | |||||
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Awards | ![]() | ![]() | ![]() | ||
Price | $379.00 at Amazon Compare at 3 sellers | $414.00 at Feathered Friends | $519.95 at Backcountry Compare at 2 sellers | $399.95 at Backcountry Compare at 2 sellers | $330 List |
Overall Score ![]() |
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Star Rating | |||||
Pros | High-quality down, warm and lofty, light, a top tier product | High-quality down, warm, lightweight | Lightweight, high-quality materials, comfortable | Lightweight, compressible, comfortable | Comfortable, lightweight, excellent materials, not constricting |
Cons | Expensive | Sizing not for everyone, fabric is a bit noisy | Expensive, included compression sack is heavy | Expensive, not particularly warm | Comforter sometimes does not stay tucked in |
Bottom Line | The premium product comes at a premium price, but is very high performing | The highest three-season performance of any model in our bunch | This bag has high quality materials, is super light, and will fit most women | A great choice for fast and light adventures, the Neutrino is comfortable and compressible | A well-priced, comfortable alternative to a mummy bag that keeps weight low on long backpacking trips |
Rating Categories | Sea to Summit Flame 15 | Egret UL 20 | Mountain Hardwear Phantom 15 | Rab Neutrino 400 - Women's | Cloud 800 |
Warmth (25%) | |||||
Weight (25%) | |||||
Comfort (20%) | |||||
Packed Size (15%) | |||||
Features (15%) | |||||
Specs | Sea to Summit... | Egret UL 20 | Mountain Hardwear... | Rab Neutrino 400 -... | Cloud 800 |
EN Comfort Rating (F) | 15 F | 20 F (not EN rated) | 23 F | 21 F | 26 F |
Fill Type | Goose down | Goose down | Goose down | Goose down | PFC-Free DriDown |
Measured Weight (in lbs) | 2.0 lb | 1.7 lb | 2.0 lb | 1.7 lb | 1.7 lb |
Total Weight (oz) | 31.2 oz | 27.5 oz | 32 oz | 27.2 oz | 27.4 oz |
Fill Power | 850+ | 950+ | 850 | 800 | 800 |
Women specific features | Women's specific fit - more insulation in key areas | Extra fill in footbox and chest | This bag comes in a "Short" length, which is a standard women's size | Women's specific fit | More insulation per square inch than men's version |
Fill Weight (oz) | 22.9 oz | 17.3 oz (medium) | 20 oz | 14.1oz | 14.8 oz |
Material | Ultralight 10D Nylon Shell | Pertex Endurance UL | 10D nylon ripstop | Pertex Quantum | 15d nylon risptop |
Neck Baffle | Yes | Yes | Yes | Yes | No |
No | No | No | Yes | No | |
Sleeping Pad Sleeve | No | No | No | No | Yes |
Zipper Length | 56" | 62" | 59" | 62" | N/A |
Shoulder Girth | 60 in | 54 in | 58 in | 60 in | 59 in |
Hip Girth | 58 in | 56 in | 52 in | 56 in | 58 in |
Foot Girth | 40 in | 38 in | 44 in | 38 in | 39 in |
Stuff Sack included? | Compression stuff sack and storage bag included | Stuff sack and storage bag included | Compression sack and storage bag included | Stuff sack and storage bag included | Stuff sack and storage bag included |
Our Analysis and Test Results
With 850-fill power goose down and lots of it, the Flame is very warm, light, and lofty. We love this bag and think it's an excellent choice for lightweight backpacking. It's pricey, but it's also widely available and firmly lands in the top echelon of women's backpacking sleeping bags we've ever come across.
Performance Comparison
Warmth
This bag is EN-rated to 15 degrees Fahrenheit, and we think that rating is spot-on. The Flame has almost 23 ounces of high quality 850 fill power down that is super lofty and fluffs this bag right up. It is neck and neck with the other top contenders in this review in this rating metric.
The Flame also has huge fluffy neck baffles around the front and back to stop any pesky drafts from coming in down your neck. Sea to Summit claims the Flame has "down chambers filled using body-mapping to maximize warmth for a woman's physiology." We're not sure what this means, but half of its baffles are sewn vertically while the lower ones are horizontal; the jury is out whether this makes a difference in warmth.
Weight
Weighing in at 1.95 pounds, this bag is not the most lightweight model we've ever jumped inside, but it's not heavy either. It's just a smidge heavier than the lightest models we tested. However, those bags are not as warm as the Flame, which makes up for the few extra ounces.
The 10D nylon shell material is very light and thin, yet we didn't experience any durability issues during testing. They are translucent—you can see the down feathers and clusters right through the materials.
Comfort
We were pleasantly surprised by how comfortable the Flame is. It is a simple mummy shape that is roomy enough to move around a bit and fit our 5'5 tester very well. It is so light and fluffy; it feels very cozy.
The spacious dimensions, yet high scores in warmth and weight, complete an ideal backcountry trifecta. You might be able to cut a little weight or gain a bit more confined warmth, but overall, this bag nails the combination of these aspects better than nearly any bag out there.
Packed Size
The Flame comes with a great compression sack that will pack this bag down super small. This bag takes a bit more effort to get into its compression sack as the materials seem to have a waterproof coating that takes effort to get the air out of when compressing it down. That said, Sea to Summit's inclusion of a compression sack, as opposed to a simple stuff sack, is a huge bonus for this bag, making stuffing it into the smallest packed spaces easier.
Features
This bag has very limited bells and whistles, which we like. The high-quality materials and streamlined design are a simple, weight-saving feature. We do wish it had a small stash pocket for those essentials like a headlamp or earplugs we want during the night. We also noticed that the zipper is not particularly high-quality and prefer ones with anti-snag pulls.
The Flame comes with a strange rectangle-shaped "case" for storage. We do not like it at all. It is difficult to get the bag back in the case, and it leaves the Flame partially compressed during storing, which is less than desirable.
Value
Here is this product's one Achilles heel - it's one of the most expensive bags we tested. This aspect is the one reason we would hesitate to buy it.
Conclusion
We love this bag and commend Sea to Summit for putting out such a technical product for women. It is top-notch in nearly every single way. We wish all manufacturers would put this much intention into new products for women. The Flame is light, super warm and lofty, and very comfortable. Now, if we could just work on getting that price tag down a bit…Regardless, this sleeping bag is a fantastic option for anyone going deep into the backcountry.
— Jessica Haist