Offering the perfect backpacking balance of comfort vs weight, our Altitude Series sleeping bags have more space than traditional mummy bags, yet still provide the thermal efficiency you need when exploring above the tree-line. The Free-Flow triple-zip design ensures your sleeping bag retains maximum warmth and efficiency when needed and multiple ventilation options when it's not. The half zip on the left side of the bag provides freedom of movement for both arms, additional ventilation and also means the top third of the bag can be folded down as a mini quilt. The full length, two-way right side zip and separate foot zip transforms the bag into a full quilt for when the mercury climbs higher than expected. If it's warmth you're after, close all the zips, pull the cord locks tight to drag everything in, and relax in luxurious comfort. The generous allocation of high quality 750+ Loft down ensures great insulation, while the oversized draft tubes prevents your body heat escaping. The panelled footbox and 3-dimensional hood make sure you're not compressing the down when you're trying to stay warm. The Altitude also features extra down overall and THERMOLITE panels under the foot area, to help keep heels and ankles warmer. Vertical baffles over the chest section ensure the down insulation cannot migrate or shift to the outside of the bag during sleep, creating cold spots. A side block baffle construction maintains the 60/40 fill ratio, keeping more down on the top of the bag for maximum insulation. Our tapered rectangular design gives you additional wriggle room inside the bag, perfect for a side or restless sleeper and an alternative if you find a traditional mummy shape too constricting. The women's specific fit is wider at the hip and narrower at the shoulder and comes in two lengths.
Offering the perfect backpacking balance of comfort vs weight, our Altitude Series sleeping bags have more space than traditional mummy bags, yet still provide the thermal efficiency you need when exploring above the tree-line. The Free-Flow triple-zip design ensures your sleeping bag retains maximum warmth and efficiency when needed and multiple ventilation options when it's not. The half zip on the left side of the bag provides freedom of movement for both arms, additional ventilation and also means the top third of the bag can be folded down as a mini quilt. The full length, two-way right side zip and separate foot zip transforms the bag into a full quilt for when the mercury climbs higher than expected. If it's warmth you're after, close all the zips, pull the cord locks tight to drag everything in, and relax in luxurious comfort. The generous allocation of high quality 750+ Loft down ensures great insulation, while the oversized draft tubes prevents your body heat escaping. The panelled footbox and 3-dimensional hood make sure you're not compressing the down when you're trying to stay warm. The Altitude also features extra down overall and THERMOLITE panels under the foot area, to help keep heels and ankles warmer. Vertical baffles over the chest section ensure the down insulation cannot migrate or shift to the outside of the bag during sleep, creating cold spots. A side block baffle construction maintains the 60/40 fill ratio, keeping more down on the top of the bag for maximum insulation. Our tapered rectangular design gives you additional wriggle room inside the bag, perfect for a side or restless sleeper and an alternative if you find a traditional mummy shape too constricting. The women's specific fit is wider at the hip and narrower at the shoulder and comes in two lengths.
Offering the perfect backpacking balance of comfort vs weight, our Altitude Series sleeping bags have more space than traditional mummy bags, yet still provide the thermal efficiency you need when exploring above the tree-line. The Free-Flow triple-zip design ensures your sleeping bag retains maximum warmth and efficiency when needed and multiple ventilation options when it's not. The half zip on the left side of the bag provides freedom of movement for both arms, additional ventilation and also means the top third of the bag can be folded down as a mini quilt. The full length, two-way right side zip and separate foot zip transforms the bag into a full quilt for when the mercury climbs higher than expected. If it's warmth you're after, close all the zips, pull the cord locks tight to drag everything in, and relax in luxurious comfort. The generous allocation of high quality 750+ Loft down ensures great insulation, while the oversized draft tubes prevents your body heat escaping. The panelled footbox and 3-dimensional hood make sure you're not compressing the down when you're trying to stay warm. The Altitude also features extra down overall and THERMOLITE panels under the foot area, to help keep heels and ankles warmer. Vertical baffles over the chest section ensure the down insulation cannot migrate or shift to the outside of the bag during sleep, creating cold spots. A side block baffle construction maintains the 60/40 fill ratio, keeping more down on the top of the bag for maximum insulation. Our tapered rectangular design gives you additional wriggle room inside the bag, perfect for a side or restless sleeper and an alternative if you find a traditional mummy shape too constricting. The women's specific fit is wider at the hip and narrower at the shoulder and comes in two lengths.
Offering the perfect backpacking balance of comfort vs weight, our Altitude Series sleeping bags have more space than traditional mummy bags, yet still provide the thermal efficiency you need when exploring above the tree-line. The Free-Flow triple-zip design ensures your sleeping bag retains maximum warmth and efficiency when needed and multiple ventilation options when it's not. The half zip on the left side of the bag provides freedom of movement for both arms, additional ventilation and also means the top third of the bag can be folded down as a mini quilt. The full length, two-way right side zip and separate foot zip transforms the bag into a full quilt for when the mercury climbs higher than expected. If it's warmth you're after, close all the zips, pull the cord locks tight to drag everything in, and relax in luxurious comfort. The generous allocation of high quality 750+ Loft down ensures great insulation, while the oversized draft tubes prevents your body heat escaping. The panelled footbox and 3-dimensional hood make sure you're not compressing the down when you're trying to stay warm. The Altitude also features extra down overall and THERMOLITE panels under the foot area, to help keep heels and ankles warmer. Vertical baffles over the chest section ensure the down insulation cannot migrate or shift to the outside of the bag during sleep, creating cold spots. A side block baffle construction maintains the 60/40 fill ratio, keeping more down on the top of the bag for maximum insulation. Our tapered rectangular design gives you additional wriggle room inside the bag, perfect for a side or restless sleeper and an alternative if you find a traditional mummy shape too constricting. The women's specific fit is wider at the hip and narrower at the shoulder and comes in two lengths.
Last updated at 06/08/2026 18:41:01
Altitude At1 Women's Sleeping Bag (-4 °C)
Free 60-day returns
Sea To Summit Altitude At I Down -4C Sleeping Bag - Womens Regular
Free delivery between Wed – Thu
Sea To Summit Altitude At II Down -10C Sleeping Bag - Womens Regular
Free delivery between Wed – Thu
originally posted on altitude-sports.com
Part of a complete Sea to Summit sleep system I put together with my partner consisting of this, the parallel Ascent 1 bag for men, and a Comfort SI double pad. An incredible setup - light, comfortable, and just warm enough for true 3-season use down to freezing if you bundle up a bit and tend to sleep warm.Great quality and design, packs incredibly small for its size (the Altitude is much wider than comparable mummy bags from most other brands). Zips together perfectly with the Ascent perfectly to create a very usable double bag that is excellent with a S2S double pad.Light enough for backpacking if you're not an ultralight fanatic, definitely comfortable enough for car camping. If you are 5'8" or taller, get the long version.Very happy with this purchase. ... MorePart of a complete Sea to Summit sleep system I put together with my partner consisting of this, the parallel Ascent 1 bag for men, and a Comfort SI double pad. An incredible setup - light, comfortable, and just warm enough for true 3-season use down to freezing if you bundle up a bit and tend to sleep warm.Great quality and design, packs incredibly small for its size (the Altitude is much wider than comparable mummy bags from most other brands). Zips together perfectly with the Ascent perfectly to create a very usable double bag that is excellent with a S2S double pad.Light enough for backpacking if you're not an ultralight fanatic, definitely comfortable enough for car camping. If you are 5'8" or taller, get the long version.Very happy with this purchase. Highly recommended.
originally posted on seatosummitusa.com
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 altitude-sports.com
I haven’t had a chance to test this cute and compact sleeping bag in the wild yet but I was happy with it’s dimensions, weight and how small it packs down. I love that I can zip down both sides and sit up in it. I found the bottom zippers a little sticky at first. They seemed to catch on each other as they over lap at the feet. I am planning to take this on summer canoe trips and I think it will be perfect.
| Snowys Comfort Rating | −4 °C |
| Lower Limit | −10 °C |
| Shape | Tapered Rectangular |
| Fill Ratio Top/Bottom | 60/40 |
| Max. User Height | 170 cm |
Altitude At1 Women's Sleeping Bag (-4 °C)
Free 60-day returns
Sea To Summit Altitude At I Down -4C Sleeping Bag - Womens Regular
Free delivery between Wed – Thu
Sea To Summit Altitude At II Down -10C Sleeping Bag - Womens Regular
Free delivery between Wed – Thu
Part of a complete Sea to Summit sleep system I put together with my partner consisting of this, the parallel Ascent 1 bag for men, and a Comfort SI double pad. An incredible setup - light, comfortable, and just warm enough for true 3-season use down to freezing if you bundle up a bit and tend to sleep warm.Great quality and design, packs incredibly small for its size (the Altitude is much wider than comparable mummy bags from most other brands). Zips together perfectly with the Ascent perfectly to create a very usable double bag that is excellent with a S2S double pad.Light enough for backpacking if you're not an ultralight fanatic, definitely comfortable enough for car camping. If you are 5'8" or taller, get the long version.Very happy with this purchase. ... MorePart of a complete Sea to Summit sleep system I put together with my partner consisting of this, the parallel Ascent 1 bag for men, and a Comfort SI double pad. An incredible setup - light, comfortable, and just warm enough for true 3-season use down to freezing if you bundle up a bit and tend to sleep warm.Great quality and design, packs incredibly small for its size (the Altitude is much wider than comparable mummy bags from most other brands). Zips together perfectly with the Ascent perfectly to create a very usable double bag that is excellent with a S2S double pad.Light enough for backpacking if you're not an ultralight fanatic, definitely comfortable enough for car camping. If you are 5'8" or taller, get the long version.Very happy with this purchase. Highly recommended.
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!
I haven’t had a chance to test this cute and compact sleeping bag in the wild yet but I was happy with it’s dimensions, weight and how small it packs down. I love that I can zip down both sides and sit up in it. I found the bottom zippers a little sticky at first. They seemed to catch on each other as they over lap at the feet. I am planning to take this on summer canoe trips and I think it will be perfect.
I'm a HUGE fan of this sleeping bag - as someone who spent years shivering through the night in old/inefficient sleeping bags, the women's specific body mapping of this bag made all the difference!The length/shape of the bag means no "dead space" (where air could stay cold), which is impressive given its not a mummy bag - there is room to sprawl a bit more. While there is extra warmth in the toes, and extra warmth around the chest (with keeps cold air from getting in), simultaneously this bag has all of the zippers you could need to ventilate on warmer summer nights (bottom of bag, both sides to make it more duvet style). The quality of the down/material itself is really nice - super soft and lofty. The bag still bags down incredibly small and lightweight as ... MoreI'm a HUGE fan of this sleeping bag - as someone who spent years shivering through the night in old/inefficient sleeping bags, the women's specific body mapping of this bag made all the difference!The length/shape of the bag means no "dead space" (where air could stay cold), which is impressive given its not a mummy bag - there is room to sprawl a bit more. While there is extra warmth in the toes, and extra warmth around the chest (with keeps cold air from getting in), simultaneously this bag has all of the zippers you could need to ventilate on warmer summer nights (bottom of bag, both sides to make it more duvet style). The quality of the down/material itself is really nice - super soft and lofty. The bag still bags down incredibly small and lightweight as needed. Genuinely don't have any critiques of this bag and would highly recommend.For reference - I'm 5'4'', and my toes don't touch the bottom of this bag but I can stay plenty warm. 125lbs, and plenty of room to wear several layers if wanted and still be able to move around.
I purchased this bag for my daughters and they love them. Perfect combination of warmth, and compact light weight for our Rocky Mountain adventures. Used for backpacking and canoe camping across 3 seasons. Very well designed and comes complete with compression sack and mesh storage bag.
I love the loft in this bag. It packs up well, but expands nicely for maximum warmth. The yoke with the separate adjustment is wonderful as I like to keep the hood loose and the yoke tight. I also find the yoke expands well to keep the cold air out especially if it is tightened to my liking.
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!)
I decided to upgrade after using an REI down bag for 5 years. And WOAH has it been a game changer. I didn't think it would make THAT big of a difference, but wow! sea to summit products are incredible and this sleeping bag is certainly no exception. most comfy sleeping bag ever! im in heaven! I just can't wait to sleep in my tent again. I have used this in 20-30 degree F temps and have been perfectly warm. THANK YOU SEA TO SUMMIT! most quality products ever! also the color is beautiful. the fabric is incredibly comfy. Buy this if you want to up your camping sleep happiness by 1000000000%
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!)
I'm obsessed with this sleeping bag for a couple of reasons. 1. the color is great and one of my favorite colors! 2. I have the 15 degree, and it's so cozy and plushy. My only comment is that it doesn't back down as small as the 25 degree, but it's something I'm willing to sacrifice for the additional plush. I'm a side sleeper and tend to roll from side-to-side, and this allows plenty of room without getting wrapped up or trapped.
| Snowys Comfort Rating | −4 °C |
| Lower Limit | −10 °C |
| Shape | Tapered Rectangular |
| Fill Ratio Top/Bottom | 60/40 |
| Max. User Height | 170 cm |
