How to Choose Sleeping Bags for Backpacking
Sea to Summit Altitude AtII 15 Sleeping Bag - Women's
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Offering a balance of comfort and weight, the Sea to Summit Altitude AtII 15 women's sleeping bag is spacious, yet it still provides the thermal efficiency you need when exploring above the tree line.
Shop similar productsKey Details
Fill
750-fill-power UltraDry Down
Temperature Rating (F)
15 degrees (F)
- Women-specific technical tapered rectangular shape creates the perfect balance of space and adaptable warmth
- 750-fill-power UltraDry Downâ„¢ certified to the Responsible Down Standard (RDS)
- Extra down throughout and THERMOLITE® panels under the foot area provide additional warmth; anatomically shaped footbox allows maximum down lofting
- Vertical chest baffles prevent down migration and cold spots
- Generously sized hood and dual cord adjustment offers maximum warmth retention
- Lightweight 20-denier nylon shell and lining fabrics offer a minimal packed size and maximum breathability
- Free-Flow half-zip left side, full-length 2-way #5 YKK zip right side and separate foot zips allow maximum ventilation and use as a quilt
- Includes Ultra-Silâ„¢ compression bag for compact storage
- Oversize draft tube with antisnag materials
- Oversize neck draft tube with dual adjustment system
- Large internal security pocket
- This bag is designed to easily zip with another (second sleeping bag sold separately)
Imported.
Temperature ratings are intended as a guideline to help you compare products, rather than a guarantee of warmth, since many different factors contribute to your comfort while you sleep. Backpacking bags are typically rated for temperature according to an independent testing protocol—currently International Organization for Standardization (ISO) 23537, though some older items followed European Norm (EN) 13537. Testing is based on a person wearing one base layer and a pair of socks, sleeping on an insulated surface with a minimum R-value of 5.38.
Each bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.
View all Sea to Summit Backpacking Sleeping BagsEach bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.
| Best Use | Backpacking |
|---|---|
| Tested Lower Limit | 1 degrees (F) - EN |
| Tested Comfort | 15 degrees (F) - EN |
| Temperature Rating (F) | 15 degrees (F) |
| Temperature Rating (C) | -10 degrees (C) |
| Shell | 20-denier nylon |
| Zipper Location | Right |
| Insulation Type | Down |
| Water-Resistant Down | Yes |
| Fill | 750-fill-power UltraDry Down |
| Lining | 20-denier nylon |
| Sleeping Bag Shape | Semirectangular |
| Stuff Sack Size | Unavailable |
| Stuff Sack Volume | Unavailable |
| Compressed Volume | Unavailable |
| Gender | Women's |
| Sustainability | Down certified to the Responsible Down Standard (RDS) |
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DebbieG
Florida
I Love this S2S bag!
4 years ago
I exchanged my quilt for a S2S bag with at 15 degree rating. Good thing too because it was cold a number of nights on the AT. My friend had a 30 degree bag, got cold and went home. I'm not a fan of mummy bags. This bag has plenty of room for the feet to move around. I'm a sidesleeper too and had no problem with this bag. On warm nights, I just slept in my bag liner with my zippers open. Their are zippers on each side for ventilation. My inflatable pillow stayed put in the bag's hood and didn't come flying out. Bag comes with a compression sack and takes a bit more room in my pack but, worth the warmth and comfort! It also comes with a storage bag. Love the color too!
Age:55–64
Weight:150–175 lbs.
Height:5'4"
Yes , I recommend this product
Kayla K.
This bag is so cozy
1 year ago
[This review was collected as part of a promotion.] This bag is so cozy and the color is beautiful. The zippers on both sides are such a great thing for me as I typically sleep facing the opposite side the zippers are on other bags and my dog crawls in to sleep inside with me. There’s plenty of room for her to do that with this bag also. We took it on our first adventure backpacking to a fire tower overnight and it was plenty warm in the 20s with my liner, wearing just a base layer. I can’t wait to take it on more adventures when the weather warms up and see how it holds up but I’m already very happy with the purchase!
Originally posted on Sea to Summit
Megan G.
Money Well *Slept* ;)
2 years ago
[This review was collected as part of a promotion.] This is hands down THE best sleeping bag I've ever owned! Well worth the investment!! I am obsessed with the color! & Its performance is immaculate! The zippers are easy to zip up & down without worry of snagging. & Even when the temps dropped during the night on my last camping trip, this fluffy bag kept me comfy & cozy all night without needing extra layers or a heater in my tent! I love my Sea to Summit sleeping system!!! (I only wish my new Aeros Down Pillows had arrived in time for this last trip!)
Originally posted on Sea to Summit
Ellie
San Jose, CA
Amazing sleeping bag!
5 years ago
I am literally cold all the time, however, this sleeping bag saved me. I took it to Mt. Shasta base camp at low 20ish F with howling winds outside our tent and I have never felt warmer! I also love how lightweight yet roomy it is. I am extremely happy with the purchase and highly recommend this product.
Age:35–44
Weight:100–125 lbs.
Height:5'4"
Yes , I recommend this product
Emily
Oakland, CA
My favorite sleeping bag yet
4 years ago
It's warm, soft, and snug while giving a perfect about of space for cozy side-sleeping. I love it's packability and even thought it's a little heavier than other bags, I appreciate all the zipper options. The ONLY thing that I would appreciate on this bag is a maybe a pillow pouch in the hood of the bag for hold my camp pillow in place. That said, it's not necessary and I have a bag liner that has one and it does the trick.
Age:25–34
Weight:125–150 lbs.
Height:5'6"
DaveP
Rockville, MD
comfy, versitile, and light
1 year ago
First time out was a car camp in lows of 40's and we zipped it together with a mens' Accent and had the therm-a-rest xtherm sleeping pads. Once we figured out the zippers to put them together it went pretty easy. The reinforced material near the zippers was helpful and comforting that I wasn't going to destroy the bag right off and when tired. The zip together made more sense when it was daylight and not after a long day. Comfort was good. The included stuff sack got made for a compact size. When ti got warm during the night, being able to zip the other side zipper was nice and made getting in and out easier.
Age:45–54
Weight:150–175 lbs.
Height:5'7"
Yes , I recommend this product
Aurora B
Reno, NV
Hard-to-please-always-freezing reviewer LOVES it!
3 years ago
Hubby and I car-camped last year in Oct. Woke up to 29°F temps, ice on inside of windshield at 5:30 a.m., shivering inside old down bag. I am always cold--even wearing heavy woolen socks at home (poor circulation in legs.) I am also a side sleeper with restless-legs. I tried out my new women's sleeping bag last night--I slept in 27° temp on concrete porch with old ½" closed cell foam yoga mat down first, then R-4.4 Klymit pad, then old woolen Pendleton blanket, finally my new bag. I wore warm leggings, fleece top, Patagonia fleece vest, woolen socks AND new Goosefeet 100% down socks. For the 1st time, I DIDN'T need a hat, neck gaiter nor gloves! I slept like a baby! I could wiggle my legs! sleep on my sides! reposition body easily! Best of all, I was NOT COLD!!! Woo-Hoo--I'm now ready to camp during the shoulder seasons. Dare I try winter camping? I DID order the Exped DeepSleep (R7.5) sleeping pad BEFORE I did my experiment. I find the R4.4 Klymit pad is fine with the extra closed cell yoga mat and woolen blank. I will experiment and try low temps with only my Klymit pad. I am VERY hard to please with high expectations. I can't believe how much I love this bag--It's warm, comfy, has good space for side-sleeper and wigglers and has great compression sack. NOTHING ruins a camping trip like being cold at night, esp if night is a long time! I couldn't be happier! I give it 10/10 stars!
Age:65–74
Weight:125–150 lbs.
Height:5'3"
Yes , I recommend this product
Meg
Great bag!
3 years ago
This bag is really comfy and cozy! It feels very light but definitely keeps the heat in! My sleeping pad failed on me on night 2 of a 2 night trip and the bag still kept me reasonably warm. I think I would pair it with one of the liners for Alberta's unpredictable shoulder seasons, but I love how versatile it is. I have tried zipping it together with my boyfriend's bag and we were very comfy, almost too warm! If I feel claustrophobic in it I simply unzip the half zip on the off side and it gives my arms a little room to splay out. After about 5 uses I am noticing some of the down coming out so hopefully this is just a normal thing and won't turn into a big issue. I also love the color (not pink!! Woohoo!)
Originally posted on Sea to Summit
Cathy T.
Best Sleeping Bag! Buy it!
2 years ago
I've had this sleeping bag for over 3 years (still going strong) and its been everywhere with me! From car camping trips to multi-day treks in all different climates, it will keep you comfy with all the different options. I thought I would want the lighter weight and more compact Flame Sleeping Bay by sea to summit, (and I am sure I would like it) however I am so glad I got the Altitude Bag instead. I love all of the options and configurations (mostly being able to unzip the foot box and stick my feet out when I want. To me It is worth the extra weight ! The bag keeps me warm when I need it and I can change the set up so I can stay cool if I need to as well. If you are considering this you will not regret buying it!
Originally posted on Sea to Summit
Shai
Maryland
I love this bag.
4 years ago
I’m a short 5’0 big girl and the size of the regular is perfect for me. Has enough space for me not feel trapped. I’ve tested it in 28-50F and it’s super nice and cozy. The zippers are so easy to use and I’m glad it doesn’t snag AT ALL! I Sleep through the night. I use this bag with a sea to summit sleeping pad and IT’S THE BEST 2 things I’ve ever purchased. I did A LOT OF RESEARCH and I’m so glad I went with this bag.
Age:25–34
Weight:175–200 lbs.
Height:5'0"
Yes , I recommend this product
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