Wearing layers in your sleeping bag....

HellsCanyon

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Been thinking about this for awhile and it seems that my personal experiences have been quite different from other's on here.

I've seen mentioned where guys will 'layer up' inside their sleeping bags to add some additional warmth to their sleep system for the night. For myself, the only layers I wear to bed are my merino base layers. It seems that anything more than that, and I actually get much colder. By only wearing my base layers when it gets cold, I am able to heat the inside air of my sleeping bag and the base layers don't inhibit me taking advantage of that warm pocket of body heat. On a few different occasions, I've layered real heavy on cold nights and have had to wake up and shed some layers to actually get my body warm...

If I indeed think it's going to get colder than my bag's rating, I'll wear my base layers, and try to add any extra jackets or clothing on top of my bag to act as another blanket and this has worked the best for myself in the past.

Anybody with similar experience?

Mike
 

6t4nova

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Yup, most of the time I only wear my boxers. I believe that the sleeping bags are made for sleeping in the nude for their temp ratings. When you sleep with clothes on, it traps your sweat and makes you more cold.
 
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HellsCanyon

HellsCanyon

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Yup, most of the time I only wear my boxers. I believe that the sleeping bags are made for sleeping in the nude for their temp ratings. When you sleep with clothes on, it traps your sweat and makes you more cold.

Thats one thing I love about my merino. Even if I sweat it still breaths and wicks better than the inside material of my bag so it keeps me from getting 'clammy' and helps regulate my temperature; hot or cold.

Mike
 

fillthefreezer

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i dont wear leayers to bed unless im trying to dry them a bit. i do pile most of my clothes at the bottom to save my little tootsies from the cold of the bottom of the bag. theyre also warm when its time to crawl out
 

Matt Cashell

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I do wear extra layers to stay warm. the key is they have to be thin enough so they aren't compressing the insulation of the bag. Long undies and thin fleece like Patagonia R1 seem to work best for me to boost my bag's warmth. I also noticed that a good breathable bivy adds some warmth. I agree totally that you need layers that breath well. Any moisture is going to have a detrimental effect.
 
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HellsCanyon

HellsCanyon

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the key is they have to be thin enough so they aren't compressing the insulation of the bag.

You're going to have to clarify that a bit Matt. I wouldn't think whatever layers your wearing would be a factor, as it is your body weight that is compressing the insulation of the sleeping bag. That is why having a good R-value'd sleeping pad is important as the sleeping bag under your body is compressed and losing its loft... Or were you talking about something else?

I've seen guys mention wearing their down jacket or pants inside their sleeping bag. Not only would this NOT work for me for reason's I mentioned in my OP, but it seems extremely restricting. I could see something like a Kifaru Doobie or something like that added either inside the bag or outside over the top to boost insulation. Is that what some of you are doing?

Mike
 

6t4nova

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Thats one thing I love about my merino. Even if I sweat it still breaths and wicks better than the inside material of my bag so it keeps me from getting 'clammy' and helps regulate my temperature; hot or cold.

Mike

Yup, that's why merino is so great. That's all I wear for base layers. Love that stuff.
 

Slim Jim

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I have a 20 degree down bag and use my sea to summit liner when it gets colder. If needed I will wear my wool base layers with the liner but nothing more because getting all clammy in your bag is the worst. I don't get to hunt up north late season so I haven't really experienced the extreme cold. I guess I better pay attention to this thread so that I'm comfortable when the day comes
 

CrzyTrekker

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Merino wool base layer and clean wool socks if it's really cold outside. Just enough to keep my skin from touching cold sleeping bag fabric, and just enough to make a midnight bathroom run if necessary.

Big believer in pads with a high R value for fall trips. The XTherm mattress is warm.
 

Matt Cashell

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You're going to have to clarify that a bit Matt. I wouldn't think whatever layers your wearing would be a factor, as it is your body weight that is compressing the insulation of the sleeping bag. That is why having a good R-value'd sleeping pad is important as the sleeping bag under your body is compressed and losing its loft... Or were you talking about something else?

I've seen guys mention wearing their down jacket or pants inside their sleeping bag. Not only would this NOT work for me for reason's I mentioned in my OP, but it seems extremely restricting. I could see something like a Kifaru Doobie or something like that added either inside the bag or outside over the top to boost insulation. Is that what some of you are doing?

Mike

Mike, this is my take:

I wasn't talking about UNDER the bag. the insulation under you is pretty much wasted because there is no trapped air there, and yes why a good Rvalue pad is essential. If you stuff your bag full of you and too much clothing, the bag insulation is going to get compressed from the inside, on the sides and top. This makes the bag less effective, and you colder.

There is no magic with sleeping bags. If you add the insulating qualities of your clothes to those of your bag, and don't negatively affect the Rvalue of the bag and/or clothes, you will stay warmer. The only way extra clothes will make you colder is if they are somehow causing your bag or your clothes to lose R value. That can happen by either holding in moisture or compressing the trapped air of the bag and/or clothing.

A puffy coat could be a problem in a sleeping bag, because there would have to be enough room in your bag for you, the loft of your coat, and still not affect the loft of your bag. That is why thin, but warm layers work best for me.

Similarly, putting something over your bag would help. as long as it wasn't compressing the loft of your bag.
 

Lawnboi

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The amount of layers you can wear all depends on how your bag fits. If your bag is tight, your probably already loosing a little bit of its ability. If its loose, you get cold air pockets.
 
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HellsCanyon

HellsCanyon

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Mike, this is my take:

I wasn't talking about UNDER the bag. the insulation under you is pretty much wasted because there is no trapped air there, and yes why a good Rvalue pad is essential. If you stuff your bag full of you and too much clothing, the bag insulation is going to get compressed from the inside, on the sides and top. This makes the bag less effective, and you colder.

There is no magic with sleeping bags. If you add the insulating qualities of your clothes to those of your bag, and don't negatively affect the Rvalue of the bag and/or clothes, you will stay warmer. The only way extra clothes will make you colder is if they are somehow causing your bag or your clothes to lose R value. That can happen by either holding in moisture or compressing the trapped air of the bag and/or clothing.

A puffy coat could be a problem in a sleeping bag, because there would have to be enough room in your bag for you, the loft of your coat, and still not affect the loft of your bag. That is why thin, but warm layers work best for me.

Similarly, putting something over your bag would help. as long as it wasn't compressing the loft of your bag.

Ah yeah I interpreted it as you talking about the insulation UNDER your body... I'm a pretty lean guy and never have quite filled up my sleeping bag so it wasn't clicking...

From my nights spent in my setup Matt, I will have to say for the first time on Rokslide, that I disagree with you. ;)

By stacking layers against my skin inside my sleeping bag, I believe that more of my body heat is spent heating up all that fabric from layer to layer and some of that heat is loss through contact. Instead of just wearing a base layer and having insulation on the top/sides of my bag (like an extra blanket or jacket or clothing), my body heats up the air inside my bag and has an easier time staying warm. One example is that if I go to bed with cold feet and I wear socks inside my sleeping bag, my feet oftentimes wake up cold. Where as if I don't wear socks, my body has heated up that air inside my bag and in the morning my feet are never cold... Just been my personal experience! Not sure if there are other factors here or not though.

Mike
 

Lawnboi

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If extra layers dont work for you. Just fill up that MSR bladder of yours with boiling water and slap it in between your legs. You will not get cold!

I guess i cant tell if layers work or not really cause iv never worn more than a couple sets of merino.

It could be that your socks and stuff hold moisture that you give off, causing you to get cold. Who knows
 

Matt Cashell

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Ah yeah I interpreted it as you talking about the insulation UNDER your body... I'm a pretty lean guy and never have quite filled up my sleeping bag so it wasn't clicking...

From my nights spent in my setup Matt, I will have to say for the first time on Rokslide, that I disagree with you. ;)

By stacking layers against my skin inside my sleeping bag, I believe that more of my body heat is spent heating up all that fabric from layer to layer and some of that heat is loss through contact. Instead of just wearing a base layer and having insulation on the top/sides of my bag (like an extra blanket or jacket or clothing), my body heats up the air inside my bag and has an easier time staying warm. One example is that if I go to bed with cold feet and I wear socks inside my sleeping bag, my feet oftentimes wake up cold. Where as if I don't wear socks, my body has heated up that air inside my bag and in the morning my feet are never cold... Just been my personal experience! Not sure if there are other factors here or not though.

Mike

Mike,

I actually think we are agreeing. It is the trapped air that insulates. You and I are saying the same thing. You need some space between you and the bag to generate the "microenvironment" of warmth. I have experienced the same thing with socks, but I bet the real reason they are cold in the morning is you perspired in them, which reduced their insulating abilities.

The bottom line is that if your feet are cold in the socks, take them off. However, if you are down to your birthday suit and still cold, you may want to try some additional insulation.
 

RUTTIN

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Another great tip I learned while hunting in Montana late season is when it is -22 F outside you can throw a couple of hand warmers in your bag. After a while you will be throwing one of them out!
 

Mckinnon

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Never more than a single light layer in my bag and a beanie. I find the beanie is the biggest factor for overall warmth for me. If my head is cold I am not comfortable at all.
 

Travis Bertrand

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Another great tip I learned while hunting in Montana late season is when it is -22 F outside you can throw a couple of hand warmers in your bag. After a while you will be throwing one of them out!

Amen! Or boil water and stick it in your nalgene. That helps as well.

I will wear merino wool, beanie and socks if I get cold but prefer skivvies.
 
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HellsCanyon

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Mike,

I actually think we are agreeing. It is the trapped air that insulates. You and I are saying the same thing. You need some space between you and the bag to generate the "microenvironment" of warmth. I have experienced the same thing with socks, but I bet the real reason they are cold in the morning is you perspired in them, which reduced their insulating abilities.

The bottom line is that if your feet are cold in the socks, take them off. However, if you are down to your birthday suit and still cold, you may want to try some additional insulation.

Yeah Matt I think we're more or less saying the same thing. And I definitely agree with your last statement... Only thing I have to add (not so much a disagreement) is that if I layer up too much inside the bag and still have to heat that 'microclimate' of warm arm, its not efficient for my body to heat that space through my layers. Layers will help keep heat in, they'll also keep heat out and I don't get to take advantage of that microclimate. I'm probably over thinking this one but it makes sense in my head... ;)

As Rock 2.0 said, a Beanie is a big factor in keeping me warm. Your body loses a substantial amount of head through your head and a quality hat or cinched up mummy hood can work wonders.

I mainly started this thread as I see a lot of guys talk about "I'll just get a __* bag and if it gets colder, just layer up!" which hasn't worked for me in that sense...

Mike
 

stephen b

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Lots of good info above.

A sleeping bag keeps you warm because YOU warm it up. The higher loft insulation of a lower temp rating bag keeps you warm because it traps more of the heat you are creating in the air pockets. So the sleeping bags keeps you warm because you are warming the air space with your body heat- this is why down does such an exceptional job of keeping us warm because it traps air so well.

As said above- fit of bag can make a difference. Too big in a cold environment and your body is either trying to heat up to much space, or there are too many cold pockets. Again- one of the main reasons a mummy bag is a super design for keeping you warm if it is the right fit.

And as Matt (BRB) above stated- if you compress the bag from the inside with too many layers, then you are affecting the bags loft and you will get cold. Also too many layers can affect possibly your ability of your body to heat the air space. A similar analogy is what is best with a hypothermic person in a sleeping bag, or when trying to warm that person up with double zip together bags. The best thing you can do in that situation is to have another person get into the other bag (2 zipped together) and have both people strip down as far as they can- for the appropriate comfort level with each other and have each others bare bodies warm up each other and the bag. IE: if it is my wife- we are going down to the birthday suits- if it is another dude, I do not care how cold you are- I will help warm you up if you are hypothermic, but we are wearing at least boxers, because we are not warming up each others nether regions. ;^)

As far as adding warm to a bag from external sources, as stated above heated H2O in bottle or bladder works well and chemical heaters work also. You can also help your bodies heating ability by having some calories taken in before bed by eating something; or you can also drink a hot beverage.

Here's what I wear and use as layers to keep me warm. FWIW.- I use down bags - mostly 30 deg ( WM Summerlite, or FF Rock Wren) or a 15 deg. if it is real cold (WM Badger). I run warm usually. To bed I wear a T-Shirt ( usually merino) and boxers ( also usually merino) and that is usually it. If it is colder I usually have with me a 4oz silk bag liner and use that with same clothes. That silk liner adds at least 5-8 degrees for me and breathes well and helps to make air space I am heating smaller and really helps keep my perspiration and grime from getting to the bag. Next in line if I am cold is longer base layers instead of boxers and short sleeve merino. Next if needed is a beanie, and or socks. The beanie really helps- and I prefer merino. And then next if I need more warmth ; and only rarely, I add either a thin fleece top or my WM down vest ( which is usually under my head to help with my clothes pillow system).

I have had to only rarely use a external source such as a heated bottle or a chemical heater as a last resort. Now my wife on the other hand- this is one of the first things I do for her to help her out. If she starts out cold, she stays cold and is not happy. So before bed if it is cold I always boil water to make her tea or cocoa and then make sure there is plenty left over to put in a bladder or Nalgene for her to put in the bag before she even goes in it and for her to use as a hot H2O bottle while in it. As they say- a happy wife, a happy life. Especially on a trip.

Well that's my 2c. (or more like a bunch more than you maybe needed based on all this typing).
 

hammer0419

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Wearing a wool base layer which breaths will by all means help greatly. Its when people bundle up and sweat is where the cold really sets in. I remember when I was little with the boy scouts having many freezing nights! We never had high quality base layers back then and froze our butts off!!!
 
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