Last updated at 15/05/2026 20:20:30
Flame Fm3 Women's Sleeping Bag (-4 °C)
Free 60-day returns
Sea To Summit Flame III Ultralight Womens Down Sleeping Bag -4C Regular
Free delivery between Tue – Fri
originally posted on seatosummitusa.com
I love love love this sleeping bag. It's beyond comfortable. I'm had some of my most comfortable nights of sleep (not just camping, but in general) in this bag. I have the 25 degree version and it definitely hasn't disappointed when it comes to keeping me warm in cold temperatures.The ultralight spec is also very appreciated -- this bag comes in handy when backpacking because it's super light -- a lot lighter than the ultra quilts that many recommend. Personally, I move a lot in my sleep so I prefer the mummy option to the quilt.5/5 stars, highly recommend.
originally posted on seatosummitusa.com
I bought the 15° bag. Used it two times in my backyard to double check temps before going to Grand Canyon (cold on the rim!) It is comfy and warm. I found it went to 30° comfortably for me. I added the down liner for colder temps, which worked down to 15° or so, with just a few cold toes (on a mat with 7+ r value), could go lower and maybe be a bit chilly. I am 5'7" /130 and decided on the long. I tried both, was really on the fence. I think I should have stuck with the regular, BUT I will say I can bring my knees all the way up in the long and that is surprising and pretty cool! It is lightweight and packs small. It's bigger than a water bottle tbh but not huge still, esp for a bag this warm. I would have liked the baffle to be bigger around my shoulders but it ... MoreI bought the 15° bag. Used it two times in my backyard to double check temps before going to Grand Canyon (cold on the rim!) It is comfy and warm. I found it went to 30° comfortably for me. I added the down liner for colder temps, which worked down to 15° or so, with just a few cold toes (on a mat with 7+ r value), could go lower and maybe be a bit chilly. I am 5'7" /130 and decided on the long. I tried both, was really on the fence. I think I should have stuck with the regular, BUT I will say I can bring my knees all the way up in the long and that is surprising and pretty cool! It is lightweight and packs small. It's bigger than a water bottle tbh but not huge still, esp for a bag this warm. I would have liked the baffle to be bigger around my shoulders but it works well enough. Zipper works great, no issues. The cinch for the hood is fine, little fussy to undo, esp if just loosening one side, but still not a big deal. Def recommend if you have the money. For the size and weight, it's a good product if you have the money.
originally posted on seatosummitusa.com
I have purchased several sea to summit products in recent years and have been very impressed with the quality. This is my first bigger purchase and I couldn't be happier. Both bags are as light as advertised (1.5 lbs bag and 8.8 oz for the size large liner) and super puffy. I plan to use the bags as a sleep system, with the 25 degree bag for most trips and the option of using the liner in addition for winter trips or alone for travel when in warm climates or sleeping on the couch.I didn't realize the liner also has a zipper part way down the side, which was a nice surprise. I chose the larger liner for more room at just one ounce more in weight; the two bags work perfectly together (except that they are really warm!). Not too restrictive, either, for a mummy bag, I ... MoreI have purchased several sea to summit products in recent years and have been very impressed with the quality. This is my first bigger purchase and I couldn't be happier. Both bags are as light as advertised (1.5 lbs bag and 8.8 oz for the size large liner) and super puffy. I plan to use the bags as a sleep system, with the 25 degree bag for most trips and the option of using the liner in addition for winter trips or alone for travel when in warm climates or sleeping on the couch.I didn't realize the liner also has a zipper part way down the side, which was a nice surprise. I chose the larger liner for more room at just one ounce more in weight; the two bags work perfectly together (except that they are really warm!). Not too restrictive, either, for a mummy bag, I find there is plenty of room. Not a fan of the rectangular storage bag but not a problem. Both bags stuff down amazingly small. Very impressed overall, great quality, can't wait to try them out.
| Snowys Comfort Rating | −4 °C |
| Lower Limit | −10 °C |
| Shape | Mummy |
| Max. User Height | 170 cm |
| Internal Girth | 150 cm Chest | 142 cm Hip | 90 cm Foot |
Flame Fm3 Women's Sleeping Bag (-4 °C)
Free 60-day returns
Sea To Summit Flame III Ultralight Womens Down Sleeping Bag -4C Regular
Free delivery between Tue – Fri
I love love love this sleeping bag. It's beyond comfortable. I'm had some of my most comfortable nights of sleep (not just camping, but in general) in this bag. I have the 25 degree version and it definitely hasn't disappointed when it comes to keeping me warm in cold temperatures.The ultralight spec is also very appreciated -- this bag comes in handy when backpacking because it's super light -- a lot lighter than the ultra quilts that many recommend. Personally, I move a lot in my sleep so I prefer the mummy option to the quilt.5/5 stars, highly recommend.
I bought the 15° bag. Used it two times in my backyard to double check temps before going to Grand Canyon (cold on the rim!) It is comfy and warm. I found it went to 30° comfortably for me. I added the down liner for colder temps, which worked down to 15° or so, with just a few cold toes (on a mat with 7+ r value), could go lower and maybe be a bit chilly. I am 5'7" /130 and decided on the long. I tried both, was really on the fence. I think I should have stuck with the regular, BUT I will say I can bring my knees all the way up in the long and that is surprising and pretty cool! It is lightweight and packs small. It's bigger than a water bottle tbh but not huge still, esp for a bag this warm. I would have liked the baffle to be bigger around my shoulders but it ... MoreI bought the 15° bag. Used it two times in my backyard to double check temps before going to Grand Canyon (cold on the rim!) It is comfy and warm. I found it went to 30° comfortably for me. I added the down liner for colder temps, which worked down to 15° or so, with just a few cold toes (on a mat with 7+ r value), could go lower and maybe be a bit chilly. I am 5'7" /130 and decided on the long. I tried both, was really on the fence. I think I should have stuck with the regular, BUT I will say I can bring my knees all the way up in the long and that is surprising and pretty cool! It is lightweight and packs small. It's bigger than a water bottle tbh but not huge still, esp for a bag this warm. I would have liked the baffle to be bigger around my shoulders but it works well enough. Zipper works great, no issues. The cinch for the hood is fine, little fussy to undo, esp if just loosening one side, but still not a big deal. Def recommend if you have the money. For the size and weight, it's a good product if you have the money.
I have purchased several sea to summit products in recent years and have been very impressed with the quality. This is my first bigger purchase and I couldn't be happier. Both bags are as light as advertised (1.5 lbs bag and 8.8 oz for the size large liner) and super puffy. I plan to use the bags as a sleep system, with the 25 degree bag for most trips and the option of using the liner in addition for winter trips or alone for travel when in warm climates or sleeping on the couch.I didn't realize the liner also has a zipper part way down the side, which was a nice surprise. I chose the larger liner for more room at just one ounce more in weight; the two bags work perfectly together (except that they are really warm!). Not too restrictive, either, for a mummy bag, I ... MoreI have purchased several sea to summit products in recent years and have been very impressed with the quality. This is my first bigger purchase and I couldn't be happier. Both bags are as light as advertised (1.5 lbs bag and 8.8 oz for the size large liner) and super puffy. I plan to use the bags as a sleep system, with the 25 degree bag for most trips and the option of using the liner in addition for winter trips or alone for travel when in warm climates or sleeping on the couch.I didn't realize the liner also has a zipper part way down the side, which was a nice surprise. I chose the larger liner for more room at just one ounce more in weight; the two bags work perfectly together (except that they are really warm!). Not too restrictive, either, for a mummy bag, I find there is plenty of room. Not a fan of the rectangular storage bag but not a problem. Both bags stuff down amazingly small. Very impressed overall, great quality, can't wait to try them out.
Absolutely loved this sleeping bag. Easy to fit anywhere. Great for kayak camping, backpacking or any outdoor sleepover. Extremely comfortable. Everything you could ask for. Our weather was to the warmer side, but I didn’t get hot. The bag kept me cool all night. Next up, cooler weather. Cheers to life outside in comfort.
This sleeping bag is amazing! I absolutely love the womens specific design, which is also great for side sleepers. This is the best sleep I’ve had in the backcountry in 10 years, and paired with the womens specific sleeping pads (I use the Ether Light XT) I find that I am way more comfortable in the hips and legs than with unisex or mens sleeping setups. If I’d change anything it would be to add a bigger baffle around the face opening, since sometimes cold air slips. I got the 15 degree and it packs down small and is very light for such a warm bag! Haven’t had a very cold night in it yet but I think it’ll perform nicely when the weather starts to bite more
Super impressed! I co-lead a collegiate adventure leadership program, Bridge Adventure. We outfitted our group with the Flame Ultralight (both mens/womens) and Ether Light XT Air sleeping pads. Through an overnight trial run in Palo Dura and 3-night trek to the bottom of the Grand Canyon, they were phenomenal. Given the light weight and incredibly small packed size, I was skeptical of the temp rating. However, the rating was spot on. Thanks Sea to Summit for helping outfit our group!
I use the flame liner together with the flame 15 as a cold weather system. It’s a compromise for me - I’m a very cold sleeper, often out in winter temperatures, and nobody actually makes a decent winter sleeping bag specifically for women. The flame 15 is one of the best bags I’ve tried so far for warmth to weight. However, I’m not big on the nylon on nylon (sleeping bag, flame liner, puffy jacket) in winter as it’s unbelievably noisy. I hope sea to summit will come out with a proper women’s winter bag that isn’t too heavy soon.
I got this sleeping bag (the 35F) last spring, and it was truly awesome throughout last year's season - really fluffy and super warm for the weight and packed size. I'm not usually camping in particularly cold temperatures so the 35F is warm enough for me, I have taken it down to 3C and with a base layer on I was nice and warm all night!However, after I stored it over the winter in the supplied storage cube thing, this spring when I took it out again it never regained that nice fluffiness it had last year. I was hoping it would bounce back eventually, but now even after a handful of trips with it this year, lots of effort put into fluffing it back up and storing it loose on a clothes hanger in between, it still hasn't bounced back and is therefore not as warm ... MoreI got this sleeping bag (the 35F) last spring, and it was truly awesome throughout last year's season - really fluffy and super warm for the weight and packed size. I'm not usually camping in particularly cold temperatures so the 35F is warm enough for me, I have taken it down to 3C and with a base layer on I was nice and warm all night!However, after I stored it over the winter in the supplied storage cube thing, this spring when I took it out again it never regained that nice fluffiness it had last year. I was hoping it would bounce back eventually, but now even after a handful of trips with it this year, lots of effort put into fluffing it back up and storing it loose on a clothes hanger in between, it still hasn't bounced back and is therefore not as warm either. This is a huge disappointment, especially considering the price tag - for this price I would expect the bag to last more than one season. If the storage cube isn't big enough for the down to retain its loft, why was it even supplied? I know you're meant to store down bags outside of the stuffsack to prevent it from losing its loft, and I've always done so, but I now wish I hadn't used the provided storage cube and had just shoved it into a normal bag instead. I miss last year's fluffiness and warmth!
I'm raving about this bag to everyone I know. I traded in my regular 15 degree bag in favor of this one, hoping that I could get a smaller packed size, but have a warmer bag. I was able to get the Flame 15 degree into the Sea to Summit compression sack (size S) and still cinch it down! When I pulled the bag out to use it, I let it loft for about 20-30 minutes and it was so fluffy and warm to sleep in! I've now taken it out 1.) winter hammock camping and shoulder season tent camping. Both the bag did really well.Random things I like:+I love that the baffles change direction to keep the heat concentrated in areas that I want it.+The hood is so comfy to rest my face against+ I like my feet have a pocket to rest in, even when the bag is completely zipped open.+It ... MoreI'm raving about this bag to everyone I know. I traded in my regular 15 degree bag in favor of this one, hoping that I could get a smaller packed size, but have a warmer bag. I was able to get the Flame 15 degree into the Sea to Summit compression sack (size S) and still cinch it down! When I pulled the bag out to use it, I let it loft for about 20-30 minutes and it was so fluffy and warm to sleep in! I've now taken it out 1.) winter hammock camping and shoulder season tent camping. Both the bag did really well.Random things I like:+I love that the baffles change direction to keep the heat concentrated in areas that I want it.+The hood is so comfy to rest my face against+ I like my feet have a pocket to rest in, even when the bag is completely zipped open.+It lofts so well+zipper is smooth+ I am tickled that I have a unique serial number for my bagThings I wish were a little better+ I don't like the zippered dust bag that the bag shipped in. I think it compresses the bag too much. I wish it just came with a normal mesh bag, like other sleeping bags.All and all, if you are looking for a luxurious 15 degree bag... I'd pick this one. I am absolutely in love.
This bag is so light and packs down so so so small! I have used it sailing and sleeping in rustic cabins so far. It is comfortable and cozy for summer camping or adventuring in places with a heater. I've even used it as a liner with another bag on top on cold nights and it worked very well. I can't wait to use it on the main salmon next summer!
| Snowys Comfort Rating | −4 °C |
| Lower Limit | −10 °C |
| Shape | Mummy |
| Max. User Height | 170 cm |
| Internal Girth | 150 cm Chest | 142 cm Hip | 90 cm Foot |
Sea to Summit's Flame range of sleeping bags has been specifically designed for women to provide high comfort and light performance for a demanding range of applications. All Flame sleeping bags are characterized by their ultra-light weight and minimal packing size as well as an excellent thermal performance. The Flame FmIII's fully sewn vertical boxing chambers contain an extra amount of down and reduce cold bridges. The expedition size of the sleeping bag provides extra space for additional layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. A full-sided zipper with two sliders allows for a comfortable fit and variable ventilation. A zipper channel, a hood and a heat collar prevent heat loss. Ultra Dry DownUltraDry Down is a PFC-free water-repellant treatment applied to the down used in all Sea to Summit sleeping bags. UltraDry Down retains over 60 % more loft, absorbs 30 % less moisture and dries out 60 % faster when compared to untreated down – which means the down will insulate better even in damp conditions. The treatment also inhibits bacterial growth, making your bag last longer.
Sea to Summit's Flame range of sleeping bags has been specifically designed for women to provide high comfort and light performance for a demanding range of applications. All Flame sleeping bags are characterized by their ultra-light weight and minimal packing size as well as an excellent thermal performance. The Flame FmIII's fully sewn vertical boxing chambers contain an extra amount of down and reduce cold bridges. The expedition size of the sleeping bag provides extra space for additional layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. A full-sided zipper with two sliders allows for a comfortable fit and variable ventilation. A zipper channel, a hood and a heat collar prevent heat loss. Ultra Dry DownUltraDry Down is a PFC-free water-repellant treatment applied to the down used in all Sea to Summit sleeping bags. UltraDry Down retains over 60 % more loft, absorbs 30 % less moisture and dries out 60 % faster when compared to untreated down – which means the down will insulate better even in damp conditions. The treatment also inhibits bacterial growth, making your bag last longer.
in 2 offers
last seen 15 May 2026
The lowest price we last saw for Sea to Summit Flame FMIII Women's Sleeping Bag (Regular) was $399.00 at Snowys Outdoors, compared across 2 retailers (last seen 15 May 2026). Prices may have changed since.
The all-time low we recorded was $349.44 on 30 June 2024.
Prices last updated 15 May 2026.
Sea to Summit Flame FMIII Women's Sleeping Bag (Regular)
Sea to Summit's Flame range of sleeping bags has been specifically designed for women to provide high comfort and light performance for a demanding range of applications. All Flame sleeping bags are characterized by their ultra-light weight and minimal packing size as well as an excellent thermal performance. The Flame FmIII's fully sewn vertical boxing chambers contain an extra amount of down and reduce cold bridges. The expedition size of the sleeping bag provides extra space for additional layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. A full-sided zipper with two sliders allows for a comfortable fit and variable ventilation. A zipper channel, a hood and a heat collar prevent heat loss. Ultra Dry DownUltraDry Down is a PFC-free water-repellant treatment applied to the down used in all Sea to Summit sleeping bags. UltraDry Down retains over 60 % more loft, absorbs 30 % less moisture and dries out 60 % faster when compared to untreated down – which means the down will insulate better even in damp conditions. The treatment also inhibits bacterial growth, making your bag last longer.
Sea to Summit's Flame range of sleeping bags has been specifically designed for women to provide high comfort and light performance for a demanding range of applications. All Flame sleeping bags are characterized by their ultra-light weight and minimal packing size as well as an excellent thermal performance. The Flame FmIII's fully sewn vertical boxing chambers contain an extra amount of down and reduce cold bridges. The expedition size of the sleeping bag provides extra space for additional layers of clothing. The vertical chambers in the chest area optimize the distribution of the down and prevent slipping. A full-sided zipper with two sliders allows for a comfortable fit and variable ventilation. A zipper channel, a hood and a heat collar prevent heat loss. Ultra Dry DownUltraDry Down is a PFC-free water-repellant treatment applied to the down used in all Sea to Summit sleeping bags. UltraDry Down retains over 60 % more loft, absorbs 30 % less moisture and dries out 60 % faster when compared to untreated down – which means the down will insulate better even in damp conditions. The treatment also inhibits bacterial growth, making your bag last longer.
