Winter Just-In-Case Sleeping Bag

The advantage to a sleeping bag/quilt over worn (or carried) garments is a much lower shell weight. The bag/quilt also has the benefit of enclosing your entire body and not letting body heat escape.

I’d pack an EE 30 degree quilt made with a 7d shell and 950 down fill for the situation you’re describing. An Enigma Custom regular/regular would weigh 13.92 oz. that’s light enough and packs down small enough to carry in a day pack

I’d carry a tent instead of or in addition to a sleeping bag.  Tent weight is about the same as sleeping bag weight.

In winter I carry a lightweight Montbell Breeze Tech Bivy as emergency backup (8oz for the Wide and Long) with a 40 degree quilt (14 oz), so I can get away with a 30-40 liter pack and and I am only taking about 1.5 lbs of extra insurance.

I’d say a tarp or other means of keeping dry is more important than upgrading the puffy to a sleeping bag.  You can do both of course.

I guess I wasn’t clear — if I’m already carrying puffy layers, a pad, and a shelter, what is the relationship between sleeping bag rating and increased chance of survival?

i.e. if I have a blue foam pad, an eVent bivvy, mid-weight down parka & pants, hardshell raingear, how much warmer will I be with a 50deg bag? a 40deg bag? a 30deg bag?

At what point does the sleeping bag not add any additional warmth?

A vastly BIGGER question is why would any human drive out to the backcountry and leave his/her car for a hike in the woods and not spend the night?????  Otherwise your day starts in a car and ends in a car—a very depressing concept.

Because certain other parties don’t want to winter camp

I must be in the minority here. I don’t carry an awful lot when day hiking, even in nasty winter conditions. Having to carry a sleeping bag, bivy or other shelter, etc. sounds like a pain for just a day hike. If you have all that, just spend the night as stated earlier. I do lots of solo overnighters just to get out there. For day hiking, I will take an extra hat, gloves, extra poofy and/or shell layer depending on forecast conditions, food, water, and a means to start fire (and the knowledge of how to do it in damp and winter conditions). There is risk involved in everything we do when we step out of our door. I may be pushing the risk a little further than some people are comfortable with, but I know my limits, I am confident in my skills, and I ALWAYS let someone know where I am going and when they should be calling in people to search for me. HYOH, as always.

There’s a tendency for dayhikers to be woefully unequipped which leads to this discussion.  Kate Matrosova and David Decareaux comes to mind—two out of hundreds.

Tipi,

Here’s a link to one of the names you mentioned.

http://www.catskillmountaineer.com/reviews-winterhikingKM.html

I have and hope to never be in conditions this bad.  I doubt that my normal day hike gear would have saved me.

Tipi said, [quote]There’s a tendency for dayhikers to be woefully unequipped which leads to this discussion.  Kate Matrosova and David Decareaux comes to mind—two out of hundreds.[/quote]

I’m reading “Where you’ll find me” about the Kate Matrosova incident now. Fascinating book. And I agree- many people go “stupid light” when they shouldn’t. But reading about Kate Matrosova has made me aware that I’ve been guilty of this too. Her hike, in terms of distance, wasn’t very long. But in terms of weather and distance in terms of hours from safety, it was extreme. I read stories like this to try and educate myself so that I don’t repeat the mistakes of someone else. Matrosova was an amazing person, it’s tragic that she died.

This discussion is all fine, but I’d like to steer it back to my original question — what is the marginal thermal benefit of climbing into a sheltered sleeping bag, while wearing all the puffy gear, as a function of sleeping bag rating?  Neglecting the impact of insulation compression, if I’m already wearing a down parka and pants, will a 50deg bag add much warmth? what about a 40, 30, 20 deg bag?

It can make a huge difference in my experience. More so when combined with a proper bivvy bag and there is no point at which a sleeping bag over the clothing won’t add more warmth; assuming it is big enough; more a question of whether the added warmth is enough.

Using the sleeping bag over the insulated clothing really adds a bigger bubble of warmth/ slows down heat loss. Mine is an old synthetic insulated summer bag; 95GSM LiteLoft and is  heavy for the insulation it gives because it has a heavy duty shell that has been  Nikwax treated to be highly water resistant. Mine is a Wet/Cold environment and I need  synthetic insulation layers and having been caught out a few times over the decades my day pack for back country skiing is now a hefty 8 kilos but for day walks below the snow line it would not be much less. In a colder and drier environment I might swap out the old synthetic bag for my Brooks Range elephants foot and change the Patagonia DAS for a down parka of the same weight but the pack mass would be similar in total, there being no substitute for a large size Goretex bivvybag.

Synthetic bag is rated 14C so +10 degrees Elephants foot -5C so +30 degrees

“Neglecting the impact of insulation compression, if I’m already wearing a down parka and pants, will a 50deg bag add much warmth? what about a 40, 30, 20 deg bag?”

A sleeping bag would definitely makes a difference due to the fact that the air between the sleeping bag and your down parka/pants becomes an insulating layer itself – as long as one isn’t wiggling around too much. Personally, I’ve pushed a 50d quilt down into high 30’s by wearing a lightweight down jacket and pants.

In my mind, bringing a 50d quilt, a 1/8″ ccf pad, (and perhaps a Gatewood Cape) on a winter hike isn’t too much of a weight penalty, and could be a potential life saver if there were ever an injury. But that’s assuming I’m going somewhere pretty remote by myself, and the conditions appear to be questionable.

“how much warmer will I be with a 50deg bag? a 40deg bag? a 30deg bag?”

If you have nothing on, you can sleep comfortably in a 80F room with no covers.  So a true 50F bag would keep you warm in conditions that are 30F lower.

But bags’ ratings don’t assume you are naked nor comfortable at their rated temperature, rather that you have some clothes on and you’re male with a high-ish metabolism.  So I’d use 65F as the reference point.  You’d be comfortable sleeping in long underwear, a puffy, and a hat with no covers at home at 65F, and a 40F-rated bag gives you 25F below that.

So I’d say a RatedF bag gives you a 65F-RatedF lower temperature than your clothing does on its own.

As requested, that is ignoring insulation compaction which is fine if you’re wearing thin clothes.  But if the clothes are puffy and the bag is tight, then that becomes a bigger issue.

Kind of like “clo” units – if the temperature is twice as far below the reference / no clothing temperature, you need twice as much insulation.  I find that most strikingly true in extreme cold (say, -40F): it’s not just another layer to be comfortable during low physical activity.  It’s twice as much clothing as you need at 20F, which was already quite a bit.

On one extreme side of the spectrum, an uninsulated bivy will add some warmth.

I’ve used a blizzard bag to supplement my sleeping bag and to use as a vapor barrier.  I’ve never used it on its own but would expect it to keep me alive in temps north of 20*f.  Uncomfortable but alive.

-25*f and we’re now talking snow cave/trench time.  Whether or not those calories are better spent self evacuating vs digging snow is a whole other conversation and would depend on if evacuation is even possible or if sheltering in place is the only option.

Your question:

“So, assuming you’ve got nice puffy layers, a pad, & wind-blocking outer layer how light of bag/quilt can you carry and still end up with a survivable overnight setup, assuming you’re uninjured, dry, properly fed, etc.?”

To -25*f?  I’d say a 0*f bag would be the low end of comfortable and a 15*f bag is pushing it for surviving, assuming that you’re fully exposed and have done nothing else to build a shelter and insulate yourself from the elements.  In a snow cave, a 32*f bag would be more than sufficient, if not comfortable.

A torso length piece of CCF pad wouldn’t be the worst idea to have in this kit.

“-25*f and we’re now talking snow cave/trench time.  Whether or not those calories are better spent self evacuating vs digging snow is a whole other conversation and would depend on if evacuation is even possible or if sheltering in place is the only option.”

I have a hard time imagining a situation in which you could dig a snow cave and not being far ahead because of it.  Once it’s done, you’re out of wind and very close to 30F.

A friend’s day trip on the Harding Ice Field turned into a 4-night ordeal.  They had a tent, sleeping bags, pads, a stove and food.  They had a locator beacon.  Jenny said the satellite locator beacon was key to the rescue, “That thing 100 percent saved our lives. We would not be here. Nobody would have found us. Nobody would have even found the remains of us without being able to get our GPS coordinates out,” said Neyman.

They didn’t have a shovel and used a ski to dig a snow cave after their tent collapsed the first night (her FaceBook avatar for the next year was a avalanche shovel).  Here’s an interview of her afterwards:

https://www.kbbi.org/post/skiers-survive-four-days-kenai-peninsula-glacier-credit-gps-locator-beacon-rescue

David,

All great points.   People have died from hypothermia on day hikes.  I’m just trying to imagine a scenario on a day hike where a snow cave and the time it takes to dig one would make more sense than just hiking out assuming I’m within 10 miles of a trailhead or other bailout option.  An injury would definitely trigger that choice.

Yes a snow cave is a great option in that case.

Some good replies on this thread.

I do the same as Lago on Winter day hikes. I pack the Montbell Breeze Dry-Tec WPB sleeping bag cover in the Long/Wide (8.3 oz) and pair it up with either an EE Revelation Apex 50  LW (13.5 oz) or a  Montbell SS down 40 (800 fill, 12d shell, 17 oz.) depending on how low nightly temps might dip. Event is too heavy for an emergency bivy IMO. The saved weight is better spent on high grade down or Climashield Apex. Super light shells for puffiy, pants and bag/quilt.

As to the need for emergency gear on a day hike, I think that it depends where you trek. The OP mentioned the NE. Most of my winter trips are in the White Mountains of NH. People have faced whiteouts, injury and other circumstances that lead them to call for rescue. But that would typically take hours on a “good” day, and who knows how long in bad weather. So I do carry a bit of added protection when below freezing. I never had to use it, so I can’t tell if it’s enough.

Also, I typically place a 50″x20″x1/4″ ccf mat in my frameless pack as virtual frame and carry outside a small cutout piece of thermarest zlite as my seat, so I have about 70″ of foam coverage. I realize it’s not enough R value to camp, but hoping that the puffy layers, oversized quilt and bivy are enough to survive if I need to stay put for a few hours.

David Phillips –

What you are looking for is the total clo for a combination of clothing plus bag. Clo and Nisley  are the key words to search for in BPL for more information.

My quick search found that 8 clo is needed to keep a typical 30-year-old warm at 20 degrees Farenheit. A 40 degree bag will add about 5 clo to the equation. Montbell Down Inner Pants will add .71 clo. A Patagonia MicroPuff will add .51.  A fleece cap will add 0.10. Baselayer clothing may add 0.5.  All of that comes to 6.82 clo. And maybe a little more because of the air trapped between bag and garments. Nonetheless, it looks like you would not sleep well. (Treat all of these numbers with a healthy dose of skepticism as I didn’t spend any time verifying them.)

These links will get you started –

https://backpackinglight.com/forums/topic/18950/

https://backpackinglight.com/forums/topic/27296/

https://backpackinglight.com/forums/topic/9378/

This subject is complex.  Back of the envelope is fine, but nothing beats sleeping on the back porch in the dead of winter to see what works for you. And pay attention to your sleep matt. It is critical to success.

Good luck out there.

Ian: Yeah, that hike or bivouac decision is tricky.  6 or 10 or 20 miles away is a car which you can crank up to 100F minutes after you unlock the door.  And while the snow cave is fabulous shelter, you only have so much food and supplies with you, your clothes aren’t getting drier, and the weather might be deteriorating.

But if the weather conditions are just too bad for the clothing / gear / navigation equipment you have along, then the option of hunkering down should be considered.

The most critical thing is to realize ASAP that things are (or might be) going off the rails, that getting home is only important goal and consider *all* your options to do so.  The time I was on a sinking boat, thankfully, the boat owner realized before I did that it wasn’t about the boat or getting home that day – it was about getting everyone out of a cold northern sea and onto land while we could still make any headway.

Staying with the original plan for too long can be dangerous.  Arguably, most of these tragedies fall into that category.

Thanks Greg! That’s the answer I was looking for.

To survive a winter day hike I’d bring a headlamp and a hand-held flashlight and just keep hiking. There’s no way I could survive an entire winter night out without a big lofty pile of down, and if I’m going to do that, I may as well plan for an overnighter.