Minimalist Approach to Warmth — Mountain Equipment Helium 250 Sleeping Bag

Post by blogger | July 1, 2014      

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Sunrise over the south west side of Stuart on the approach hike.

I woke up shivering, soaking wet, without a sleeping bag, lying on a ledge high on the granite massif of Mt. Stuart here in the Cascades. It wasn’t an unplanned bivy, or an emergency. Instead, I was shivering in the name of light-weight, in my unwillingness to lug a heavy pack.

Two days previously, my climbing partner Kirk and I had weighed the decision of carrying our heavy sleeping bags up the route, as opposed to significantly lightening our packs. In the warm comfort of my living room it was an easy decision to not bring the sleeping bag, just an emergency blanket bivy sack. Up on the mountain, I wasn’t so sure. But I did know my standard 0 degree bag would have been overkill, so after that night I became convinced of the utility of a super-light summer bag.

This year I’ve been testing out the Mountain Equipment Helium 250 sleeping bag, one of ME’s lightest bags. The bag cuts weight in all possible ways, resulting in a fairly warm, 25 ounce unit. The packed bag is about the size of a small bread loaf. It is rated for a comfortable night’s sleep at 32F (0C), with an “extreme” rating of 5F (-15C). The Helium is stuffed with 280 grams of 750 fill down (check this out for details on down fill ratings). It also features a complex baffle system, and a tight cut (saves additional weight for a skinny guy like me; might not fit everyone).

This is the first bag I’ve owned that is rated for a higher temperature than 15F. I’ve always been wary of ultra-lightweight sleeping bags opting instead for the insurance of heavier, warmer bags. I often carry minimal warm clothes on overnight trips, reducing weight a bit to allow for a big warm bag. A good night’s sleep is important, and in the event of an emergency, having a super warm bag can be essential. However, a light, low insulation bag has its place.

Three of Mountain Equipment's lightweight bags.  Helium 250 in the middle.

Kept us warm at the Asulkan Hut on Rogers Pass. Helium 250 in the middle.

I’ve had the Helium for a few months now and used it on a variety of trips. It’s perfect for hut trips, as it’s small, but still warm enough to stay cozy when the cabin gets a little colder in the middle of the night. Originally I thought the bag would be good for huts, warm summer trips, and little else. But on a few overnight trips this winter the little stuff-sack proved too tempting, and I took it instead of my heavy winter bag. With some careful techniques, the bag kept me sufficiently warm on a late winter and spring campouts. The bag is also small enough to easily carry while traveling, which I’ve found useful for couch-surfing, and unplanned nights in airports.

How to day warm at high camp while keeping your pack light?  Testing ground: Rainier, Kautz Camp 2.

How to stay warm at high camp while keeping your pack light? Testing ground: Rainier, Kautz Camp 2.

Of course, being a down bag, the Helium’s major weakness is water. On all my trips I’ve been careful to keep the bag as dry as possible, so moisture hasn’t been an issue. However, I’ve purposefully not brought it on trips without a tent, or with any chance of getting the bag wet. Also, the zipper, fabric, drawstring of the bag are lightweight and hence don’t seem all that durable. I’ve been careful with the bag and I tend to be fairly easy on my gear, so I haven’t had any issues so far. But it’s something to be aware of.

Other thoughts about water: Perhaps this type of sleeping bag should be constructed using water resistant down, which would make it safer for alpinism. Water resistant down can be less lofty, but once a bit of moisture comes into the picture the fluffiest down available starts to collapse anyway, and quickly gets dangerous. Further, perhaps the outer shell could be a super lightweight membrane type fabric that would be more water resistant. The Helium shell does repel water in a “bead off” fashion, but most certainly is not water resistant enough to block persistent wetting. (If I’d brought it on Mount Stuart, to be safe I probably would have used a waterproof, breathable bivy sack as well to protect it from moisture.)

I originally thought this sleeping bag would have limited use, only as a light bivy bag or for trips in warmer climes. However, since I got the Helium I’ve used it more than any other bag I have, and it’s not even deep summer yet! I’m looking forward to testing it out on summer climbing and hiking trips.

(WildSnow Editor’s note: A reliable source from Mountain Equipment tells us they offer another bag which is essentially the same as the Helium but more waterproof. The Matrix range of sleeping bags have both waterproof down (on the top of the bag) and Primaloft (on the bottom). The Matrix I is heavier than the Helium 250 (32oz vs 25oz) mainly because of the Primaloft on the bottom (which increases comfort when sitting on wet snow or other damp surfaces). The Matrix I is also slightly bulkier but Mountain Equipment designed it specifically for bivy use like Louie is referring to in the beginning of this review. According to Mountain Equipment, Matrix I could be used without a bivy sack on a misty belay ledge or in a drippy snow cave, but not if you’re not trying to sleep in a rainstorm.

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Shop for 12 oz. waterproof breathable bivy sack here.


12 Responses to “Minimalist Approach to Warmth — Mountain Equipment Helium 250 Sleeping Bag”

  1. Lisa Dawson July 1st, 2014 4:48 pm

    About a year ago I suffered through a sleepless night on the surprisingly cold floor of the Denver International Airport. Since then, I always travel with a Mountain Equipment Helium 400 sleeping bag in my carry-on bag.

    Three subsequent flights were delayed overnight and I was mighty glad to have a sleeping bag along. Lou was happy too since I didn’t grouse too much about his tight fisted aversion to hotel rooms.

    Best airport for an overnight bivy: newly remodeled Terminal 3 at San Francisco International Airport.

  2. Glen July 2nd, 2014 6:27 am

    Thanks for the review but IMHO it’s just too risky to go with down, especially because with one mistake, be it an unexpected storm or a leak in your pack and you ‘re SOL. For just a few more ounces, why didn’t you go with the Matrix and isn’t there a purely primo light bag out there that is in that weight category?

  3. Lou Dawson July 2nd, 2014 8:59 am

    Glen, I agree, quite a few people have died over the years due to down sleeping bags getting wet. Something that handles moisture better is much safer. The new water-resistant down products actually work surprisingly well, but they’re still not like synthetics such as Primaloft. I have a Dynafit down jacket with water resistant down, I’ve been amazed at how well it works when damp. Lou

  4. Louie III July 2nd, 2014 8:21 pm

    Good point! I agree, synthetic bags are much safer, on many trips, they are definitely the way to go.

    On some trips, however, it’s wouldn’t be life threatening if your down bag got wet, just uncomfortable (ok, maybe heinously miserable, but you’d survive). In my opinion, it’s very situation dependent. For example, on that Stuart trip, I survived the night without a sleeping bag already, so having a light one along would essentially be a luxury that turned the night from miserable to comfortable. On the Rainier trip, I might have gotten too cold that night if my sleeping bag had gotten wet. However, I could have skied down to the safety of the parking lot (and the ranger station) in 1-2 hours.

    Also, we have impressively accurate weather forecasting in Washington. In my experience, it’s more accurate than Colorado, where you often get afternoon thunderstorms out of the blue. If it’s 100% chance of sun, it would be a challenge to get your bag too wet to use. However, if the weather’s questionable, or you’re shooting for a tight weather window, synthetic is the ticket.

    Also, hot water bottles are great for emergencies, and can keep your body temperature high, as long as you have a stove with fuel.

    Sometimes that light down bag in it’s cute little stuff sack is just to light to refuse 🙂

  5. Louie III July 2nd, 2014 8:23 pm

    The Matrix looks great! I might have to check that out.

  6. GearX July 6th, 2014 9:58 am

    Another thing to think of when going with a lightweight bag is sleeping bag liners. Some, like the Reactor series from Sea to Summit will increase your performance rating by up to 25 degrees. They use Thermolite, which has a really good weight/warmth ratio. Liners like this work really well by themselves on summer trips or bummin’ it on a buddies couch.

    Yes, the downside of down is definitely the whole getting wet thing. New “dry-down” bags are definitely an improvement over reg. down, but should still be treated very cautiously (dry compression sacks) Some people tend to think that your bag is ruined once it gets wet, not the case! You can throw it in your dryer with a tennis ball or a shoe. This breaks up the down clusters inside the baffles and helps distribute them. Of course, this doesn’t help you on your trip. You don’t want to resort to this on a regular basis, and if you are..maybe synthetic is a better choice.

  7. Phil July 6th, 2014 6:24 pm

    Down still rules the roost. heh heh.

    We all know that this has been debated ad nauseum over the years. And, perhaps surprisingly, although synthetics have improved, the best warmth:weight, compressibility:weight, durability & comfort STILL comes with down. As long as you are careful with it (and having a dry loft shell helps) there are very very rarely any problems. And I’m speaking from the perspective of living in the Pacific Northwest and doing long (3+week) ski traverses and sea kayak trips.

    All my bags are now down. The one synthetic bag I’ve used wore out (lost loft) in about 4 years of quite regular use. In comparison, I’m still using a 30 year-old down bag! It has lost a bit of loft, but is actually in quite amazing shape!

    Certainly, there are very specific usages where synthetic is warranted and is much safer. People likely know if that means them.

    I would love to see some quantitative testing results on the coated (water resistant ) down. I’ve got a puffy with it and seems to work well. However, I doubt it is the miracle solution. I don’t know what the durability/longevity issues are with it. It costs more. You lose some of the loft, so the warmth:weight ratio isn’t as good and therefore, it will be closer to the best synthetics in that department….

    Other questions? Test results anyone? Or experiences?

  8. Jim July 7th, 2014 5:54 pm

    I have a Feathered Friends Vireo which works great to about 15F and add your down jacket, and puff pants if colder. Its just a tube with a drawstring, no zip and only about 17 oz. Key is tightening the drawstring to keep warmth in.

    I won’t deal with the guy at Nunatak ever again…very bad experience with him but they make a tube bag also.

  9. JCoates July 8th, 2014 4:55 am

    I have a Gortex ultralight bivy sack (MontBell) that I take everywhere with me–summer or winter. I’ve used it twice without a bag for unplanned bivys and I use it when needed with a light-weight down sleeping bag to increase the warmth ratio. I’ve camped in mid-winter in the Alaskan interior (below 14K feet) with a sleeping bag rated at 25 degrees and never had a problem. I think you get a better weight to warmth ratio this way and it protects you somewhat from heat loss related to moisture that you lose with a down bag. If you use a good bivy sack, I really can’t see any reason why you would ever need a heavier sleeping bag than 20-25 degrees for almost anything short of above 20K feet…and even this is questionable. I know Ed Viesters said he never used anything warmer than a 20 degree bag on his climbs (of course he was sleeping in a down suit as well).

  10. Taz March 30th, 2016 3:47 pm

    I think a lot of the comments in this review are a bit pointless sorry.

    It is clearly not an alpine bag, so why would you want it to be suitable for alpine use? To be so would make it heaver, bulkier and more expensive which then defeats the purpose of getting it in the first place.

    As for down vs synthetic, that’s nothing to do with the bag either.

    Thank you for all your good points and information on the bag though. I am about to purchase one, which I will use with a liner when required for extra warmth =)

  11. Mike March 30th, 2016 3:58 pm

    Lou, my new tlt radical binding heel just lost the big grey screw and whatever was in the hole. I could lift the heel off the post. I did back that screw off quite a bit as i like my bindings to release easily. I’ve skied about a dozen times and just noticed it gone today. I had recently shaved off the top of that anti-twist gizmo but i don’t think that had anything to do with the screw coming out. Do you know if it’s as simple as getting replacement parts that go in the hole (spring, etc) and just putting the screw back on (tighter!) or is it more complicated than that?

  12. Lou Dawson 2 March 30th, 2016 4:33 pm

    It probably popped out due to not enough threads being engaged. Might be repairable if you get the parts, but there is a pretty good chance it’s not, as once those threads are mucked up it’s really hard to twist the “big grey screw” in without cross threading it. BTW, we call that a “spring barrel” or “spring barrel cap” or something like that (grin).

    Sorry to hear about this. Clearly, you had backed it off too far, as believe it or not I’ve never heard of this particular mode of failure, and we’ve been running these things for years, even with kids.

    Next time, if you want ultra low lateral release just take the center spring out of the spring “pair” that’s under the spring cap. But also know that if you run with super low spring tension the heel unit can easily lift up off the center spindle.

    ‘best, Lou

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Welcome to Louis (Lou) Dawson's backcountry skiing information & opinion website. Lou's passion for the past 50 years has been alpinism, climbing, mountaineering and skiing -- along with all manner of outdoor recreation. He has authored numerous books and articles about ski touring and is well known as the first person to ski down all 54 of Colorado's 14,000-foot peaks, otherwise known as the Fourteeners! Books and free ski touring news and information here.

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