Cold wet night, advice for next time

[KRS]

Hey all, A couple of weeks ago I was able to get out for a quick weekend overnighter. I was exited because the weather was calling for snow with temps in the low 30’s something I never get to experience on trips. I brought my EE 20 down quilt, GG foam pad and my Klymit Ultra Light V air pad. The shelter was a tarp with a ground sheet (plenty of ventilation). I was on the AT here in VA, so on the ridge line of the mountain but under tree cover (not a summit point). The weather started just as I was getting to bed, mostly cold rain. I was dry and the shelter did its job not allow any weather to get in and hit me. I woke about 4 hours into my slumber freezing and feeling damp and for the rest of the night I didn’t sleep. I do not know the actual night time temp but the rain turned to snow and covered the ground with about 2″ of a wet sticky snow by the time i woke. Im feeling like my problem was from condensation inside the bag. I usually don’t camp in the winter or the shoulder seasons, but I have camped in very cold conditions but never with precipitation in the mix. This is a new problem to me, I usually stay completely dry and comfy. What did I do wrong or is this just that annoying temp that requires much wisdom? Besides the sleepless night and not being very comfortable it was a great trip, Loved the snowy morning.

[Ben C]

AT in that weather is really hard to keep a dry bag.  I have had similar experiences.  Really damp cool air hits your bag and condenses on it.  One option is an overbag.  A light one is fine.  Synthetic makes a lot of sense for the overbag. The overbag gets wet and hopefully leaves your main bag dry. Another option is a bivy, but you can still get a little wet.

[KRS]

Ben, when you say an overbag do you mean another quilt over the top of my down quilt? I have been thinking of buying a MLD (net head) Superlight Bivy for a while to upgrade my sleep system and add some bug protection in the summer. Do think that would have helped in the above situation?

[Jerry Adams]

was there condensation on the outside of your quilt?

or was it perspiration condensing on the inside?

[KRS]

Was there condensation on the outside of your quilt?

or was it perspiration condensing on the inside?

 

Both I think, the outside was damp/wet but the down was not lofting like normal, Im assuming that the down was damp as well. It felt like the outer layer of down in the quilt was more flattened than the inside down. Had about half the loft as normal. Thought that to be weird since i had only been asleep for around 4 hours. Thats a lot of body condensation!

[Matt Dirksen]

Kurt,

Sorry to hear about the cold/wet night. At least it didn’t dampen the rest of your trip. Having hiked a lot on the AT in the VA/MD/PA, it sounds like you were sleeping in cold-ish temps with the perfect dose of Mid-Atlantic humidity to ruin your slumber. Often, cold/humid conditions can prove to be more dangerous than colder/dryer conditions, since moisture saturated air is such a conductor of heat.

While I certainly believe an overbag/liner would have significantly helped, I’m additionally curious on a few other symptoms not reported on. Namely:

1. At any time before you woke up did you ever feel like your underside was not quite warm enough? Was the foam above or under your Klymit?
2. When you got home, what was the condition of your sleeping bag when you pulled it out? Did it still seem wet to the touch? Did the down inside still seem wet?
3. What else were you wearing, (a warm hood/hat or something?) and did you ever drop your head inside the quilt at any point, to try to get warm?
4. Was it a DownTek quilt, or regular down?

Matt

[Lester Moore]

The combination of a bivy sack and a VBL is a pretty effective combination against cold, wet, humid weather. The combination protects the down inside your quilt from both the outside moisture and from your body’s moisture, plus it adds 10 degrees or more of warmth to your sleep system’s lower comfort level. Pretty clammy and uncomfortably inside a VBL unless it’s well below freezing though. People either tolerate or hate VBLs it seems – don’t know anyone who really likes them.

[Ben C]

Kurt, yes, I mean an extra quilt over the top.  When it is really humid, it’s going to condense. The overbag hopefully collects the condensation.  I have had the exact thing happen to me.  I think an overquilt will work better than a bivy but the bivy can help.  On the downside, the bivy keeps some of your self-generated moisture inside.  Any way you do it, those are tough conditions for keeping dry.  Try to dry out your overquilt the next day if possible.  All this is assuming you are getting external condensation instead of body-generated moisture, and I think that’s the case.

[KRS]

Matt,

1. At any time before you woke up did you ever feel like your underside was not quite warm enough? Was the foam above or under your Klymit? Answer: The foam was under my air pad, I know its better on top but I like the protection it offers for the air pad. I keep it centered under my core. I never really felt cold from the ground but but my whole body was chilled equally when i woke.
2. When you got home, what was the condition of your sleeping bag when you pulled it out? Did it still seem wet to the touch? Did the down inside still seem wet? Answer: I was able to air dry it in camp before i packed it, so when i got home it felt slightly damp but wouldn’t loft up. I stuck it in the dryer for a while after that it was back to normal.
3. What else were you wearing, (a warm hood/hat or something?) and did you ever drop your head inside the quilt at any point, to try to get warm? Answer: Clothing I was wearing UA heat gear boxers, Cap light weight long sleeve crew, Cap thermal weight bottoms and cap thermal weight hoody, fleece hat, (hood was over my hat), Smartwool expedition weight socks, When I woke I added my down jacket which helped warm me up.
4. Was it a DownTek quilt, or regular down? Answer: I don’t remember if that was an option back when i bought it, so Ill say no. So let just assume it regular down.

[Jerry Adams]

You could weigh your quilt when you got home, then after it dries to see how much water there was in it

[David Thomas]

Those are tough conditions to stay warm in.

As Jerry asks about and Lester offers a solution (VBL) to, I suspect the biggest issue was perspiration from your body, condensing within the down.

You say the shelter worked well.  With a tarp (and trees) over you, the outside of the quilt wouldn’t have radiant-cooled below ambient temps.  I’m seeing only one mechanism for atmospheric humidity to condense on the quilt – if there was no wind and your breath brought up the humidity inside the tarp, then it would condense somewhere – mostly on the tarp, but some on the quilt as well.

OTOH, moisture from your body definitely migrates through the quilt and condenses within the quilt and on its outer fabric.  Even when you’re not exercising, you lose some moisture from your skin.  Your skin and the inside of the quilt are at about 90F.  The outside of the quilt was at about 30F.  As humid air from near your skin migrates through the quilt and as the water vapor molecules diffuse through the quilt, more and more of it will condense as it moves to colder, outer layers of the quilt.

Solutions: Vapor-barrier liner inside the quilt.  Synthetic quilt or at least dri-down.  I’ve pondered using a snorkel-like mouthpiece plus some tubing to exhale outside of one’s bag and tent but I doubt I’d sleep well like that.

[Paul S.]

David covered it well, but I would add that your bottom insulation sounds way too light for the conditions.

The more heat you lose below you the less heat you have to push your dew point to our quilt shell and you could get more condensation in the insulation layer.  Could be wrong here, hopefully someone more scientific can weigh in.

[KRS]

Just curious would a silnylon rain jacket work as a VBL ? I also have the Montbell Dynamo wind pants that are a pretty tightly woven would those come close to a VBL in a pinch? Trying to see if I used thing I had with me if I could have prevented this. Looking like some new gear may be in my future for next year to get in some early season and late season trips in. A lightweight synthetic quilt would not be a bad purchase as I could definitely us a lighter quilt for summer. A MLD Superlight bivy is also on my shopping list. Any recommendations of where to get VBL clothing and links how to use VBL clothing?

[Jerry Adams]

google “vapor barrier sleeping bag liner”

you can use a plastic garbage bag as an experiment to see how well it works.  Holes for your arms and neck.  A vest.

https://www.warmlite.com/product-category/clothing/

I got some “fuzzy stuff” from warmlite and made pants and shirt.  Comfortable against skin.  I didn’t think the warmth for the weight was useful

[David Thomas]

“Just curious would a silnylon rain jacket work as a VBL ?”

Anything that leaves you soaked in your own perspiration come morning would work (that’s why VBLs are never popular, even if they are sometimes helpful/necessary).  Anything that breathes or lets moisture through ultimately wets out your quilt.

So think about kitchen trash bags with a head hole cut out.  And bread bags (that one-pound bread loaves come in) over your feet, under your socks.  Or make your own, cheap, VBL with 2-mil plastic sheeting (painter’s “drop clothes”) and some package sealing tape.  You think want to wear clothing between you and that air-tight layer, but the closer the VBL is to your skin, the more of your insulation it will keep dry.  If you wear anything under it, at least use only thin and easily dried materials like poly-pro tights.  You’re trying to keep that moisture, (condensed, alas) on your skin and out of your clothes and quilt.

A 4″ x 6″ piece of micro-fiber towel can be used to sponge yourself off in the morning and repeatedly wrung out.  Heck, start your stove, make some warm water, and give yourself a sponge bath afterwards with that some patch of towel.

VBL works.  It’s not fun, but it works.

[MJ H]

Anything that leaves you soaked in your own perspiration come morning would work

Calculus final?

[Erica R]

It does indeed seem the problem was condensation within the bag. Do you think a synthetic insulation would have performed better then down?

[Jerry Adams]

Synthetic much better than down when wet.

Down loses loft when it gets wet so loses almost all warmth.  Depending on how much of the sleeping bag gets wet.

Synthetic loft remains the same.  Although it loses some of it’s insulation value because the water in the insulation gets evaporated which takes some of the heat.

[Matt Dirksen]

Kurt,
Given that the temps were effectively right at freezing, and you were already dealing with mixed precipitation, you were confronting the worst of all possible combinations: just the right amount of cold with the wrong amount of moist, humid air. In your situation, (sort of like the opposite of a cold soda can on a hot-humid day) it’s not a question of IF condensation will occur, but where.

Let’s assume your skin temp is 90d, and the outside air around your quilt is mid-30’s. Also, let’s assume that the RH is 90/95% (which is highly likely when you’re sleeping on the wet ground under a tarp while it raining & sleeting.) The dew point is going to be just a degree or two under the ambient temperature. And as the night goes on, the air continues to humidify and the temperature drops a degree or two. You keep adding your breath and body moisture to the ambient air around you, and you are now dealing with fully saturated air.

Given what you described, it sounds like the ambient humidity impacted the down’s loft in the quilt enough to cause you to become cold halfway through the night. A better insulated pad would have certainly helped, since your body wouldn’t have to work so hard keeping your underside “balanced”. (In cold weather, I always put my ccf pad above my air mattress. Just that change can make a measurable difference, as shown here.)

And as Ben suggested, I believe a second “sacrificial layer” would be very useful, because the dew point would have likely migrated into the outer bag. And if the outer bag’s insulation were synthetic (or water resistant down), it wouldn’t be subjected to as much loss of loft. Most of my trips over the last 30 years have been in the Mid Atlantic. When I’m sleeping in the shoulder seasons – between 45d – 30d, I’ve had a lot of luck with a simple silk bag liner that I put over top of my quilt – to help distribute any condensation that will occur – either from droppings from the fly overhead, or the air itself. However, in your situation where it was colder (and wet), I would have definitely used an overbag.

Regarding VBL’s, I personally don’t have any experience with them, and I leave the VBL advice to others who have experience with them. But given all I’ve read and what I understand from your situation, it doesn’t sound to me like a VBL would have not been helpful in your situation.

A warm body inside of a VBL but sleeping on the ground under a tarp in 95-100% ambient humidity would still generate condensation somewhere directly outside of the VBL – just from the saturated moisture in the air itself.

Andrew Skurka is arguably one of the foremost experts on using VBL’s. He’s made it pretty clear to his readers when he believes VBL’s are most effective, based on his experience. When asked by a AT thruhiker about using a VBL on his NOBO trip – starting in February, his response was:
“In general, temperatures on the southern AT in mid-February will not warrant VBL’s.”

Hope this helps,

Matt

[Ben C]

I really think this is external moisture (dew) rather than internal condensation from your body.  Westerners don’t get the conditions you’re describing a lot.  But in the east, those conditions mean dew on the outside of your sleep system.  I really don’t think any kind of VBL is going to help.  I have slept in an open AT shelter in those conditions.  Everything in the shelter was wet in the morning. But you do get to choose what’s on the outside that gets wet. That’s why the light synth bag makes a lot of sense.

[KRS]

Well I have done a lot of reading on VBL’s (Andrew Skuhka’s website) and it seems like the temps I’m in normally might be to warm for it. On that note, I have a mummy style space blanket thats now going in the pack for those conditions. I think that is easier than VBL clothing. As per the outer quilt I think that will be my next purchase. I will get use out it in mid summer so its a sound investment. I was looking at a synthetic rated at 50 degrees, would that work? Like I said earlier the MLD Superlight Bivy is still something I’m shopping for, so by next winter I think I’ll be pretty set if i encounter these conditions again. So thats 3 bullet I didn’t have. I will also take Matts advice on the closed cell pad onto of the air mattress. Trips like this are why I started backpacking and getting everything dialed in will definitely get me out more often in those conditions. Thanks for the help everyone,

[Edward John M]

The described conditions are pretty much what an Australian winter is a lot of the time. One of the better ways to tackle the problem is to carry more weight and use a good double skin tent with good ventilation flow and to use a water resistant sleeping bag cover or highly breathable bivvy bag and simply adjust to the fact that sometimes it is going to be a miserable night. Tent condensation is sometimes unavoidable but the use of a cover to minimise or avoid condensation inside your sleeping bag works for me. Temperatures with-in a few degrees of freezing with high humidity will almost always see me sleeping in a full layer of fleece as well as my base layers and also see me using a Tyvek liner as a partial VB.

It isn’t Ultra-Lite as most people understand it but it is a light as the circumstances dictate; although this winter I have a new system to try out using a combination quilt from Nunatak which may work, an Arc-Lite quilt with a WR Robic shell and APEX insulation and the overquilt will replace the bivvy bag.

In the circumstances outlined in the OP I would have fired up the stove and made a cup of cocoa in the middle of the night and added another layer of clothing

[Katherine .]

I’d say your problem was a Klymt V + Quilt combo. Did not work for me. I know you had the GG in the mix too, but if it’s the 1/8 that’s still not that much. Klymt’s web copy makes it seem like letting your bag fill those wide welded bits is bonus insulation. But I think it’s part of their equation for the supposed R value. They were nice about taking mine back at least.

I tested it car camping a few years ago on a coolish May night. 20 degree EE rev + ***insulated** Static-V. Could totally feel the cold coming up. Grabbed a spare RidgeRest and tucked it under me and felt a clear difference.

So that explains the cold, an perhaps the cold begat the damp.

 

[M B]

Seems to me that

 

1.  You really didn’t have enough pad to start with

2. You used a quilt that was marginal for the conditions regardless of the weather

 

The conditions were such that yes you were going to experience loss of Lost because of the high humidity and cool temperatures.   For a overnighter, or several day trip,  the easiest way to mitigate it would have been to bring better insulation all around.

 

Vbl it’s for longer trips when you don’t have the ability to dry out here insulation and it accumulates it until it doesn’t work anymore.  There’s no need when there’s way more comfortable options to use on a overnighter, unless you’re just experiment ing

 

[Lori P]

I used one of those Klymit pads – froze, ditched it and went back to Exped, problem solved. I have been using a Jacks R Better Hudson River for 12 years. I knew it was not the quilt.

[Author]

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