How do you sleep in your quilt – with some layers or no layers?

[Murali C]

I recently read on some reddit thread that the warmest way to sleep was to not wear any layers and let your skin be in contact with the down bag. It sounds like solid advice. I have always slept with an OR echo like shirt, puffy and some thin wind pants.

[Jerry Adams]

That’s the warmlite.com theory

I prefer to wear my warm clothes that I wear during the day, and wear them inside quilt also, to save weight – I don’t need as heavy a quilt/sleeping bag

I always wear long sleeve shirt and pants to absorb body oils to protect the down

Then I wear a vest or two depending on how cold it is

If you’re in a sleeping bag, it has to be big enough to accommodate the extra volume.   I suppose the same would apply to a quilt.

[Kevin Babione]

I too sleep in clothing for a couple of reasons:

• To protect the quilt and my hammock from my body oils (and smells)
• So I don’t have to put something on if I get up in the middle of the night

What I wear is pretty limited – Usually the shirt I’m planning to wear the next day for hiking and, as long as they’re not too muddy, my hiking pants.  If it’s going to be cold I throw on an appropriate hat for the temperatures and I’ve been known to put my puffy on backwards (unzipped with the zipper under me) if it’s really cold.  Having puff under you does nothing to keep you warm.

[Philip Tschersich]

If you wear enough layers to compress the down in the quilt (from the inside pushing out), then that will reduce the effective R value of the overall sleep system. With a proper sizing and differential cut to the quilt (the circumference of the quilt inner material is less than the shell) and with clothes that add dead air space between you and the quilt without compressing the insulation in the quilt, you increase the R value of the system. Your clothing likely has a lower R value than the quilt, so having the clothes compress the insulation in the quilt is going in the wrong direction. There is nothing about quilts that defy thermodynamics. You want to increase the dead air space thickness, and thus R value, between you and the environment to increase warmth. You can accomplish this by wearing clothing, acknowledging the above caveats.

I usually sleep with a minimal but full base layer (‘longjohns’) here in Alaska, and will add layers as needed based on temps I encounter, especially by adding a puffy sleeping hood.

[Todd T]

It’s simple physics, and the physical laws don’t suspend themselves in the wilderness.  Additional insulation in the form of clothing will reduce heat loss and make you warmer than if the sleeping bag (or quilt) were the only insulation.

However, like many myths, this one grows from a seed of truth.  In this case it’s two or maybe three seeds.  First, and most important, if you sleep in the clothes you hiked in, you almost certainly will be colder than if you sleep naked, because the clothes you hiked in are almost always damp from sweating in them all day.  It doesn’t take much dampness–even just a damp waistband on your underwear–to make you cold at night.  The bellows effect brings cold air into your bag/quilt every time you move, and if you’ve got damp clothing against your skin, you will feel it.

Second, when you crawl into your bag, you usually have cold extremities (hands and feet).  Those will need to warm up before you’ll feel warm overall.  If you’re naked, your extremities can acquire heat from the rest of your body more quickly, both because your body warms up the inside of your bag faster and because your extremities can “see” or even touch the rest of your body, so it can seem that you warm up faster.  In reality, when your hands and feet warm up, they’re getting the heat from your core, so it’s a zero-sum game.  Once the initial hand and foot warming is over, which happens in maybe five to ten minutes, you’ll be colder the rest of the night without your additional clothes.

A third possible seed of truth is the potential that whatever clothes you’re wearing are so thick that they result in excessive compression of your sleeping bag’s insulation (maybe less an issue with a quilt).  It would probably take an odd set of circumstances to make that happen–a too small bag with very compressible down and heavy but poorly insulating clothes.

What I do:  I always carry “pajamas” to sleep in (baselayer top+bottom usually).  I never sleep in anything I hiked in, especially not anything with a waistband (i.e., underwear).  This not only keeps me warmer, but keeps my bag clean, so I do it regardless of the temperature.

[Matthew / BPL]

Agreed about the simple laws of thermodynamics but there is at least one caveat I am aware of. I used to get cold feed when sleeping in the cold and someone mentioned that my socks might be too tight. I have found that very large socks or no socks at all seems to fix my cold feet at night. I would guess that means that constricting clothing on one’s legs or torso might have a similar impact.

[David D]

I change out of my wet clothes including skivies as soon as my tent is up and then put on dry base layers (alpha top, lifa bottom)..

That way I go to sleep dry and in prewarmed base layers and I offset weight by using lighter mid layer in camp between arriving and bed time, with no loss of warmth

Only time I sleep without clothes if it’s hot at night (above 60) and this cools, not warms me up.

[Todd T]

I would guess that means that constricting clothing on one’s legs or torso might have a similar impact.

Absolutely.  Maybe not as much as for socks and gloves, but yes.

[Jerry Adams]

I wear my slightly damp clothing inside quilt and it dries pretty quickly

If my socks are wet, I’ll put on my spares and try to dry out the wet socks over the next 24 hours

[JG H]

So many variables here…. Are you a hot or a cold sleeper? What is the r-value of your sleep pad? Are you sleeping in a breezy tent (Duplex) or one that pitches low to the ground and retains heat better (XMid)? Even things like being a back-sleeper vs a side-sleeper and campsite selection can have an impact on what you may have to wear to bed.

Short answer: I sleep in as little as possible, but always in at least a t-shirt and boxers. That said, I’ve also slept comfortably in a puffy jacket, alpha leggings w/tights underneath, and down booties and been toasty without sweating it out. That’s the exception, though, as my rule for sleep attire remains “less is best”.

[Jerry Adams]

“Are you sleeping in a breezy tent (Duplex) or one that pitches low to the ground and retains heat better (XMid)?”

That makes sense

It would be interesting to get data on that.  Air temp outside the tent.  Air temp inside the tent right above or next to your sleeping bag.

[David D]

I was assuming cold temps.  If it’s warm enough out, I keep my wet clothes on with a breathable fleece on top to bake off the sweat before bed.  If it’s in the 30s, that gets pretty uncomfortable fast and I’d rather bake off the sweat the next day on the move

[Dustin V]

I often wear a puffy in the quilt for the same reasons as above, but also to allow for some modulation during the night. I start with the quilt pulled up until I warm up, then push it down when I get too warm. With a puffy on, I’m not going from too warm immediately to too cold. Then when temps drop overnight, I pull up the quilt again and can add clothes out of my pillow sack if needed.

[Dan]

I agree with Philip and Todd about the thermodynamics thing. More insulation = warmer.

[Kevin M]

I’ll always throw base layer top and bottoms in with my sleeping bag for sleeping in. Either just a thin synthetic one if its in the summer, or a warmer set if its colder months, and at the very least I’ll always sleep in that.

Because it’s in the dry bag with my sleeping bag it means I always have something dry to wear no matter what’s happened during the day, it helps to keep my mat and bag a bit cleaner, and means that if I need to go pee or if I need to get out quickly for whatever reason, I have at least something on and don’t need to faff about loads.

Obviously if it’s colder outside I many add to that and have down booties, jacket, hat etc. But the base layer will always be a minimum.

Kev

[tkkn c]

With layers,

unless my layers are wet, or it is really warm

Try both with and without layers

[Matt Dirksen]

+1 to everything Todd said. It is truly fascinating how myths can emerge from grains of truth!

I also believe folks woefully underestimate the impact of the bellows effect coupled with vapor management. As an architect, a rule of thumb I often communicate with clients is that a square inch of air gap is equivalent to about eight square feet of no insulation in a wall assembly. (Not to thread drift, but I believe mattress manufacturers are not properly accounting for body movement on an air mattress during the night and the profound effect of the air circulating and “mixing” with the cold edges. )

Either way, a thin layer can not only add a little R-value, but will promote much-needed moisture management through the night, which can greatly reduce the potential for conductive heat loss.

This has not only been proven time and time again to be more effective over the years, but the ISO/EN temperature ratings require the test mannequin to wear them as well. In other words, if someone is “not” wearing a thin base layer (and about R-5 of insulation underneath of them), they should NOT expect their sleeping bag to perform as specified.

[Bill Budney]

As well discussed above, it depends, but you won’t have to wash your quilt as often with at least a thin layer. Avoid constriction, especially in extremities.

How do you sleep in your quilt – with some layers or no layers?

On the warmest, most humid, nights, I use a bag liner as a sheet and go commando.

All other times, at least a thin base shirt and shorts, mostly to protect the quilt (unless it is cold enough to require extra layers).

Warmlite makes expedition bags with VBL liners rated to -60F/-50C, so their advice may be special.

[Jerry Adams]

from reading warmlite, they talk about how on an expedition of many days at very cold temperatures water will perspire out of the body and then freeze inside the sleeping bag.  After days, the sleeping bag will be much heavier and will lose warmth.

If you have a vapor barrier close to your skin, then the perspiration will never flow out into your sleeping bag so it won’t gain weight and lose warmth

So the case where a warmlite bag would be good, is many days at very cold temperatures, like on an arctic expedition.  I think well below 20F.

[Paul McLaughlin]

Using a VBL creates a special case, because you do not want extra clothing inside the VBL; it would absorb the moisture you are generating during the night and be damp in the morning. An good reason to use VBL clothing instead of a VBL liner, if you want to use VBL. That way you have the option of wearing clothing over the VBL if you need additional insulation.

[Terran Terran]

If your clothes are cold does it take longer to warm up?

[Jerry Adams]

I think it doesn’t matter if it takes a while to warm up.  When I first go to bed, my metabolism is faster so I have extra heat to warm my sleeping bag.  If I wear extra insulation, I’ll wear it before I go to bed so it will be warmed up.

The time I feel the coldest is in the morning.  The temperature typically gets colder over night so it’s coldest in the morning.  My metabolism gradually slows so it’s the least in the morning.  It takes a while for me inside the sleeping bag to cool.  From experience, the times I’ve felt coldest was in the morning.  Sometimes, I’ll just give up trying to sleep and get up so I can move around and warm up.

If wearing damp clothing, some heat is used up evaporating water, so the effective insulation value is cut by about half.  As it dries out, the effective insulation value increases to normal.  This will make you feel colder when first getting into bed, but not in the morning.

[David D]

Skurka has a great article about the benefits of VBL clothing over VBL bag liners, but his use case is unique as he traveled many continuous days in nasty temps

[Terran Terran]

If my clothing is cold, there’s greater mass to warm up. If my quilt is adaquate for the conditions, I don’t need the extra insulation. While I end up warmer or too warm, initially I’m colder.

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