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Therm-a-Rest Haven Sleeping Bag

Therm-a-rest Haven - Top View
Therm-a-rest Haven – Top View

The Therm-a-Rest Haven is a special type of sleeping bag that doesn’t have any back insulation. Called a Top Bag, all of the insulation in the Haven is located on top of your body and along the sides, because insulation and fabric you lie on can’t retain warm air and is just dead weight.

Therm-a-Rest Haven - Bottom View
Therm-a-Rest Haven – Bottom View

Designed to be ultralight, the Haven weighs 1 pound 7.8 ounces (684 grams) and contains 700 fill power down with a temperature  rating of 20F.  As a point of comparison, my 20F degree down sleeping bag, a Western Mountaineering Ultralite weighs 1 pound 13 ounces, so an appreciable weigh difference if you are trying to trim your gear weight.

No Zipper

The Haven does not have a zipper which helps save weight but makes the bag a little challenging to get in and out of. If you’re very thin, you could slide through the top of the bag past the hood to get in and out. My shoulders are too wide for this and I can only get in by sliding in from the back.

Sliding in from the Back
Sliding in from the Back

Sleeping Pad Integration

For maximum warmth, Therm-a-rest recommends that you slide your sleeping pad inside the Haven. Since I have to get in from the back, I start by sliding my pad into the Haven’s footbox, and then sliding my feet in on top of it. I enter the Haven from the back and pull my head into the hood.

Head thru the back
Head thru the back
Finally, I reach behind my back and fold up my sleeping pad in order to slip it under the elastic behind my lower back.
Folding up the sleeping pad to slip it inside the top end of the Haven
Folding up the sleeping pad to slip it inside the top end of the Haven

This is much easier to do with a thin Therm-a-rest pad like a Women’s Prolite instead of an Neoair Xlite (shown above), and if you are a large person, you want the extra space inside the Haven that the thinner pad provides. I like sleeping with the thinner Prolite pad inside the Haven the best, because the elastic around the Haven’s back hole forms a perfect seal with the pad and eliminates any side drafts.

The other option is to get into the Haven (again from the back) and simply lie on top of your sleeping pad. This does not eliminate side drafts however and Therm-a-Rest only recommends it as a warmer weather configuration. The Haven comes with a pair of straps that let you secure an external pad over the back hole, but these are only practical to use if you can slide in through the top hood. They tear off very easily however, so I’ve removed them entirely (1.2 ounces) and let the walls of a single person tent keep me on the pad.

In the Haven, on top of the sleeping pad
In the Haven, on top of the sleeping pad

The Hood

The Haven has a hood like a sleeping bag, but it has a curious design. It has a cinch cord, so you can pull the perimeter of the hood tight, but this has the effect of lowering the top of the hood over your eyes rather than pulling it in closer to the sides of your head like a traditional mummy bag.

Flat and wide hood
Flat and wide hood

The same cinch cord is also used to control the space between your chest and the top of the bag, but does more to flatten the hood and narrow the breathing space, rather than narrow the space around your chest. It would be better if the hood and size of the chest opening were controlled separately as they are on most sleeping bags.

Pulling the hood over your eyes
Pulling the hood over your eyes

No Draft Collar

Unlike many mummy bags, the Haven lacks a draft collar which is a tube of down or synthetic fill that drapes across the top of your chest and prevents the hot air heated by your body from flowing out around your neck when you move at night, the so-called “bellows effect.”

Create a draft collar by tying a sweater or jacket around your neck
Create a draft collar by tying a sweater or jacket around your neck

If you plan on using the Haven in 20-30F degree weather, the lack of a draft collar is unfortunate because you will be cold at night. One way to mitigate this is to make a poor man’s draft collar by tying a sweater or insulated jacket around your neck so that it fills the space where a draft collar would normally be placed. This works very well and is a neat little trick for warming up a sleeping bag at the low end of its temperature range.

Poor man's draft collar prevents hot air from escaping
Poor man’s draft collar prevents hot air from escaping

On the flip side, I can understand why Therm-a-rest left the draft collar off the Haven – because it would make the bag much too hot in warmer weather. Without a zipper there is no effective way to vent the Haven and having a draft collar would make it even more unbearably hot in warmer weather.

A Plus for Side Sleepers

It’s easy to sleep on your side in the Haven because the hood is flat and wide and will vent your exhalations without collecting condensation. Contrary to what you might expect, rolling onto your side does not bring the back pad or back of the Haven off the ground – you simply rotate inside, as long as the pad you are using is inside the Haven and held in place by the elastic surrounding the back hole.

Sleeping Warmth

I have taken the Haven down to the mid 30’s at night and remained quite comfortable, wearing long underwear, a fleece hat and a fleece top. I reckon I could take it down at least into the high 20’s with a poor mans draft collar to keep the body heat from escaping out around my chest.

However, when temperatures are in the high 50’s, the Haven has a tendency to become a little to warm to sleep in without removing more of my sleeping clothes. In even warmer summer temperatures, I would avoid using the Haven for sleeping because it is impossible to unzip and vent. The hood and collar also makes it difficult to use as a quilt or blanket because they get in the way of draping the Haven over your chest and shoulders.


The Haven works best when used in cooler temperatures (35 – 55) with a thin pad than can be slipped into the top bag and prevent any side drafts from reaching the occupant. Without a zipper, the Haven is difficult to vent in very warm weather when a regular lightweight sleeping bag or down quilt would be a much more flexible option. Still within a cooler temperature range, the Haven is a comfortable sleep system, and a lightweight one, provided you use a lightweight sleeping pad.


  • Good for side sleepers
  • Provides more head insulation than a regular sleeping quilt


  • Narrow temperature range/hard to vent in warm weather
  • Sleeping pad straps are easy to pull off back of bag where sewn
  • Doesn’t have a separate draft collar
  • Thick sleeping pad limits interior room if slid into the footbox

Disclosure: Therm-a-Rest provided Philip Werner ( with a sample Haven Top Bag for this review. 

Manufacturer Specifications

  • Size Tested: Regular
  • Weight: 22.8 ounces / 648 grams (on the scale)
  • Fits: Up to 5′ 10″ (178cm)
  • Girth Shoulder: 60 in / 152.4 cm
  • Girth Hip: 60 in / 152.4 cm
  • Girth Footbox: 40 in / 101.6 cm
  • EN13537 Comfort: 30 F / -1 C
  • EN 13537 Comfort: Limit 20 F / -6 C
  • EN 13537 Extreme: -10 F / -23 C
  • Fill: 700 Goose Down
  • Fill Weight: 10.6 oz / 300 g
  • Liner Fabric: 100% Nylon Taffeta, 30 denier. Fabric is calendared to achieve down-proofing.
  • Shell Fabric: 100% Nylon Riptop, 20 denier, DWR finish


  1. The tiny weight saving seems hardly worth it, given how inflexible the “bag” is. (not really a bag is it, with a giant hole in it?) A simple thin bag would suit me in a wider range of conditions (if hot open it out, if cold wear clothes in addition to bag) but I would say that as I like to be able to move about while I sleep and enjoy the cushioning of a bag under me. Thats not dead weight to me.

    • Really like the fact that manufacturers are exploring alternatives, but I really don’t get this one.

      My Western Mountaineering Megalite long weighs 1lb 10oz but is super flexible…I use it opened up as a quilt when it’s warmer, as a bag when it’s colder and can move all the down to the top of the bag when it’s really cold. Rated at 30 deg, I’ve slept soundly on a 1st gen NeoAir down to 18 F with a med weight baselayer and fleece hat. The cut of the bag is near perfect, as is the hood and quality is second to none.

      If you have a very specific need that this item satisfies, great! But for all around utility I just can’t find a better bag than my WM.

  2. I didn’t really get this bag either until I slept in it. Then its merits really stood out. It has a limited temperature range which is an issue, but I use plenty of other gear that is also special purpose, so I really can’t hold that against it.

    1) It really is a sleeping bag not a quilt because of the hood. Another clue is that it has an EN13537 temperature rating, which you can’t do on quilts.

    2) the side sleeping benefit is worth noting. I have a really hard time doing that in a mummy bag, which is why I switched to quilts this year. This bag gives you the benefit of a mummy (hood), a good temperature range compared to a quilt in lower temps, and the ability to sleep on your side.

    No doubt – it’s a bit odd in construction, and it’s not for everyone, but it does work pretty well in a narrow range.

  3. Having froze my butt off in the Whites in all seasons more times than I care to recall, this product looks drafty enough to never personally consider.

    • That may be true, but I slept comfortably in it over the weekend despite horrific weather. Truth is my quilt would have been too cool this weekend and my full sleeping bag too hot.

  4. I really like the concept of this and it seems like a really clever design that would be useful in a lot of situations. It sounds like it probably packs very small as well since there is no insulation in the back so that is definitely a plus. I just feel like this would be a tad limited in some applications like you mentioned not having a zipper. On warmer nights it is nice to just unzip completely, so the versatility of this is somewhat limited compared to a more traditional design.

    By the way I really like the pictures in this post. It really illustrates how to use the product properly and nice to see in a review such as this.

    • It actually packs a little smaller than my quilt – close to the size of a Nalgene. I think a 1/2 or even a 1/4 zip would make this massively more functional, but would diminish the airtightness of the seal that is made with a sleeping pad when inserted into the ‘hole’. It’s pretty remarkable how draft free the attachment is – I was impressed!

    • Great pictures! I kept thinking “it can’t be, it can’t be, it is!” My brain wouldn’t believe that someone would build this, but the images left me in no doubt.

  5. I like Big Agnes’ execution of this concept down to and including the 3season models like the Lost Ranger but I don’t think their cold weather bags work well enough.

  6. it looks like very difficult just to get into it :)
    i cant imagine if you suddenly need to get out very fast from that bag, like in the middle of the night, lol

  7. I have been intrigued by the Haven in the past, but reading your review It seems like a lot of trouble for not that much weight savings.

    • Big Agnes bags aren’t that much different…it’s not like top bags are a new concept or anything.

      • Do Big Agnes have the big hole in the back though? I think thats the main source of amusement here. Why have a big old mess of elastic underneath you if you could have a smooth, draught-free and lightweight underside? Just seems like an unnecessary risk to me.

  8. I’ve read other reviews that make it sound like getting in and out is quite the production. I like the idea of a good quilt for side sleepers, (don’t the majority of people sleep on their side?) but this looks like too much work just to get a good sleep.

  9. That was a great review, thank you.

    I agree a draft collar and a smaller head hole would be minor changes that would make this a way better product. I have used the Haven about 20 nights, over 300 miles. I never use it with a mattress inside, only on top of a mattress, under a tarp, and if it’s wet out or windy I add a bivy. The bivy protects the down from moisture and totally cuts out cold drafts. My base pack weight is less than 14 lbs.

    If you look at the Haven from a sleeping bag perspective, you might see a big hole and no zipper. If you look at this as a blanket or comforter, you might see a comforter that tucks itself in on the sides and comes with a hood. I think it helps to look at your sleeping bag or blanket as only one component of your sleep system. The mattress can play a more important role in maintaining warmth all night.

    The Haven allows for direct contact with the mattress, this helps keep you centered on the mattresses and maintaining the warm area. The foot box and hood helps keep the top insulation in place, as oppose to a loose blanket that might move away. If you are using a mattress with reflectivity the only way to get the full benefit is to remove the insulation barrier between you and the mattress.

    Before the Haven I used the Western Mountaineering Highlight at 16oz. It fit and was warm to its intended 35F temperature. The main problem with most sleeping bags today is sizing. If a bag fits right it can translate to less insulation and weight. Bags that are roomy and big need to have more insulation to work and at a less efficient temperature than the bags original intent. Tucking the Haven underneath, closing the hole, automatically sizes the bag to the right fit or at least the right girth.

    As for temperature range, too warm is easy to manage. I stick my leg out the hole in the bottom. Almost like sticking my leg out from under the comforter at home. When I’m cold I resist the temptation to go into the fetal position, I lay on my back to maximize both the top insulation and the mattress. When I’m not cold or start to get warm I sleep on my side, with my head out the head hole and use the hood to hold clothing for a pillow. The hood also folds forward when you are on your back by stretching the hole elastic from the front of the chest or neck, around to the back of the shoulders and under the arms.

    Getting in and out the hole in the bottom of the Haven is simply a matter of sitting up, effectively shortening the distance between your feet and your head. Guaranteed not to hide or jam like a zipper and can be a bit easier, even faster.

    My name is Jim Giblin, I designed the Haven and my views expressed on this web/blog post are mine along and do not necessarily reflect the views of Cascade Designs, Inc.

    • Cool response! Good points, well made.

    • Jim – thanks for chiming in. I find it very valuable to understand the design and how best to use the product. Cascade should get you (designers) to write the product documentation and do the product videos, too. :-)

      From your comments, it sounds like you assume that the user will be able to slide through the neck opening to get out – no other way if you are attached to a pad. That was a show-stopper for me because my shoulders are too wide. Should the sizing be modified or better documented for individual differences? Does the longer sized haven have a larger neck opening?

      You also mention the hole elastic. Are we talking about the neck hole? Mine doesn’t have any elastic – just the string and cord lock which control both the hood and neck opening.


  10. Thank you Phil,

    The Haven is certainly a mind bender for many people. The reactions have been all over the chart.

    Unless you are serious about dropping pack weight you might never consider compromising your sleeping bag. But those who have already been using blankets, quilts, comforters are willing to consider the Haven.

    I’m 6’ and 200lbs, I don’t enter or exit the head hole and I don’t use the straps. I use my body weight (and height) to keep and hold down the edges of the bottom hole. I only use the bottom elastic hole to get in and out of the Haven.

    The bivy adds a whole other level of security and versatility in cold or wet weather. So all together, the Bivy, with Reflective Air Mattress, and the Haven adds up to about 3lbs. and comfort well below 20 degrees.


  11. I hope you understand that I share your frustration. The original thought process was to sell this as an alternative to the sleeping bag. This required that we addressed the fear of the hole by inserting the mattress and/or adding straps. Lesson learned is that you can’t find customers for the Haven by talking to people who still use sleeping bags.

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