thermal illusion: don't wear clothes in a sleeping bag?

[paul wheaton]

When I was young and camped, I stripped naked, got in my sleeping bag and would be warm as toast til morning.
Years passed without camping.
Then I go to a family reunion at the family cabin. We're all older and have our own families. There are way too many people to fit in the cabin, so lots of us will be outside. I bought a tent and four sleeping bags for my family. That night, I got into my sleeping bag with all my clothes on. And was damn cold all night. The temperature probably got down to 40. Everybody else was fine. Since we were staying a few more nights, I popped into town and got a super heavy duty sleeping bag. Much better.
Time passes.
This past weekend I took my son's boy scout troop to a boy scout camporee. So out with the tent and sleeping bags again. And again I get in with all my clothes on. It got down to 25 and I suffered all night.
The next moring I call my wife and ask her to bring out my ski pants.
The other adult on the trip says: either strip naked, or put on fresh clothes before getting into bed. There is moisture in your clothes that is keeping you cold.
It seems like the clothes I'm wearing outside are doing a decent job of keeping me warm. It would seem that if I wear the exact same thing and get into a sleeping bag, I would just get warmer. But thinking back to when I was younger, it seems I wore less and stayed warmer. So maybe this is true and just seems contrary to what would work.
I know I'm going to end up doing more camping like stuff in the near future with the boy scouts. And it's only going to get colder (the beginning of January is the klondike winter camporee, and later in January is snow caving).
I'm confused and not sure if I should risk the strip-down approach. I could use some advice here. Anybody have some magic words that will make everything make sense in my head?

[fred rosenberger]

I went camping once. they told us to not wear anything in our sleeping bags. i didn't listen.
i was warm all night, but... the next morning i froze. i guess i was used to having ALL that insulation on, so when i got out of the bag, it was like taking off my coat. i froze all morning.
the people who did sleep without their clothes on seemed fine.
so, i'd recomend not wearing clothes, not for the night time, but to make the next morning easier.

[Bert Bates]

Absolutely -
No clothes or very loose, light clothes, you know, jammies
No tight socks, no tight long underwear, loose, loose, loose. I also agree with the moisture comment. Another very cool (warm) idea is the silk sleeping bag liner - fairly inexpensive and warm, and easy to clean, and keeps your sleeping bag clean.
welcome back!

[HS Thomas]

Just add a couple of pairs of swim trunks, and subtract everything else. ...Then in the morning unzip sleeping bag and take a flying leap into freezing pond. Trust me, you'll be warm as toast all day.
The Swedes do it without swim trunks. sychos!
regards
[ October 27, 2003: Message edited by: HS Thomas ]

[Jessica Sant]

also -- a sleeping pad is KEY. It does 2 things for you:
1- it erases some of the rocks you're lieing on
2- it insulates you from the ground. If you have your bag right on the ground -- the ground will suck a lot of the heat right out of your bag.
You don't need a big blow-up pad, just a little something. Therm-a-rest is a great brand. They have pads that range from $20 (foam pad) to $140 (self-inflating cushy pad) and everywhere in between. I work very part-time at EMS (Eastern Mountain Sports) -- you can check out the kinds of pads we sell here.

[Marilyn de Queiroz]

I've observed the same phenomonon. I, perhaps wrongly, attributed it to the idea that the heat was trapped inside my clothes and couldn't get out to warm up the sleeping bag. As I slept, my body temperature dropped, and since there was no stored heat, I got cold. Now that I'm writing it down, it sounds kinda strange.

[paul wheaton]

The other adult on the trip, Leon, was telling me that I should put on the underwear that I'm going to wear the next day. Based on everything I'm reading here, that sounds like it jives with what the rest of you are saying.
I think I'll pass on the freezing pond thing. I have two ponds, and I'm not too excited about jumping in them in the summer!
As for pads: I had an air mattress, but was told that air mattresses are comfy, but they do a poor job of insulating. Rather than one big air cell, you need millions of little air cells. Besides, that air mattress was huge and the electic air pump seemed a bit out of place in the "roughing it" scene. Everybody else on the trip brought everything they needed in a backpack. My son and I had to make four trips to the car. How embarassing!
I remember reading one time that "cotton kills!" So maybe I need to find clothes have less cotton and more ... silk, wool and synthetics?
So just to sum up .... On my first night, I wore my clothes inside my sleeping bag and I was cold. If I had taken all of those clothes off and put on the exact same clothes, but they were clean, I would have been warm. Is this correct? Further, if I had stripped naked, I probably would have been warmer. Am I on the right track?
It sounds like there is something goofy about dirty clothes that makes you cold while you sleep. They are a bit damp or something. Plus, based on what HST says, the act of getting briefly chilled might kick in your internal furnace. Yes?
It sounds like we have a lot of evidence, now I would just like to wrap my head around the "why".

[Gail Schlentz]

When I camp with the Girl Scouts, we tell them to put on fresh clothes to keep warm at night because of the moisture thing. I also tell them to put their clothes for the next day in the bag with them - that warms them up so you're not jumping into icy cold clothes!

[paul wheaton]

Originally posted by Elaine Micheals:
When I camp with the Girl Scouts, we tell them to put on fresh clothes to keep warm at night because of the moisture thing. I also tell them to put their clothes for the next day in the bag with them - that warms them up so you're not jumping into icy cold clothes!

And that leads to a good question: How often do girl scouts camp? How different is girl scouts from boy scouts? This boy scout troop meets Tuesday nights for an hour, AND they generally have some activity going on three weekends out of four. AND one of those weekend activities is usually an overnight camping trip.
My wife and I talked a little about scouting for our daughter too, but she seems to get out plenty for horse camp and other horse related activities. So we're thinking of just letting it go.

[paul wheaton]

Another question ....
I roll around a lot while I sleep. I remember when I was younger and had one of those small sleeping pads, the pad and I would often get separated at night. Now that years have passed, do they now have some way of attaching the back of the sleeping bag to the pad?

[Gail Schlentz]

Originally posted by Paul Wheaton:

And that leads to a good question: How often do girl scouts camp? How different is girl scouts from boy scouts? This boy scout troop meets Tuesday nights for an hour, AND they generally have some activity going on three weekends out of four. AND one of those weekend activities is usually an overnight camping trip.
My wife and I talked a little about scouting for our daughter too, but she seems to get out plenty for horse camp and other horse related activities. So we're thinking of just letting it go.

It depends on the individual troop that she gets into. Our troop used to camp a couple of times per year, but has become more interested in "camping" at lodge-type campgrounds instead of tent camping. Some troops prefer not to camp at all, and others are hard-core backpackers. It just depends!

[Marilyn de Queiroz]

Agreeing with Elaine. It depends on the troop leaders, where the troop is (urban or rural, east or west) and the parents of the scouts.

I do think that it is commonly expected that boy scouts will "rough it" more frequently than girl scouts.
[ October 28, 2003: Message edited by: Marilyn de Queiroz ]

[Marilyn de Queiroz]

http://outside.away.com/gear/gearguy/200306/20030612.html
http://outside.away.com/gear/gearguy/200307/20030711.html
http://www.trailspace.com/backcountry/messages/17518.html

Wear wool, not synthetics (unless you're allergic to wool). Linen is pretty warm, but most synthetics will make you feel colder than ever.

According to

this thread, it would appear that there still is no way to keep the sleeping bag on the pad to date. Maybe you should invent a way.
[ October 28, 2003: Message edited by: Marilyn de Queiroz ]

[Dave Vick]

'Cotten Kills' or 'cotten is rotten', either way, it is true. Cotton, when wet, has no insulating value. Wool is great or a synthetic like polypropelene that will wick the moisture away from your body.
As far as the whole sleeping bag thing, I've heard the same thing about not wearing clothes in it. My understanding was along the lines of - 'if you wear all of your clothes to bed, what ar you going to put on in the morning to keep yourself warm with?'.
A couple of things I've found to be really helpful when sleeping in the cold:
--eat something just before you go to sleep, doesn't have to be anything big, a candy bar or some handfulls of trail mix.
--make sure you have an empty bladder - why spend all that good quality warmth on urine? Even if it is zero dark thirty and you have to go, get up and go, you'll be warmer for it.
-- depending on the type of sleeping bag you have, make sure you fluff it up before crawling into it. Especially if it is one those that comes in a stuff sack. The air inside and around the insulating material adds even more insulation.
--As was mentioned, a sleep mat. An air one isn't too bad, air is a decent insulator, especially in that type of use because the air is not circulating and it prevents you from losing heat through direct contact with the ground. There are all sorts of good, inexpensive synthetics too. Heck, go to an old surplus store and get an old military Isopore mat -they work fine. And you can probably get one for just a couple of bucks.
Thats all I can think of right now....
hope it helps

[HS Thomas]

Paul : plus, based on what HST says, the act of getting briefly chilled might kick in your internal furnace. Yes?
The idea is to jump in and out quickly. Avoid getting hypothemia at all costs. The heart stops at beating at 20 degrees C, I think.
The Swedes go from sauna to pond and it's the changes in temperature which make it endurable. It's also a tradition at St Andrews(Scotland) on May Day to jump into the sea at 4am. Fortifying whiskies and fires at the end make it endurable.
So I don't think this is suitable for normal camping conditions if the water is very cold.

But I do have two very sensible tips.
Wear a balaclava while sleeping in the sleeping bag. 40% of heat is lost through the head. Don't sleep with your head fully inside the sleeping bag as moisture is lost through breath,and collects in the sleeping bag making it damp.
regards
[ October 28, 2003: Message edited by: HS Thomas ]

[paul wheaton]

Marilyn,
All of those articles appear to advocate wearing clothes to bed. And those guys sound mighty hard core.
I wonder about my age and the lowering of my metabolism ...

[Rufus BugleWeed]

People were not meant to sleep in tents in 25 degree weather.
Thermal underwear, a sock cap, socks and three dogs is all you need for a three dog night.
How much moisture could you have in your clothes, I don't think so.
I like all of Jessica's recommendations.

[Richard Hawkes]

I can't understand why you don't just get your man-servant to pump hot air into the tent with the bellows. I mean, they're going to be up all night keeping the fire alight anyway

[HS Thomas]

Paul Wheaton : wonder about my age and the lowering of my metabolism ...
Rufus BugleWeed : People were not meant to sleep in tents in 25 degree weather.

There's been a shift in what the Boy/Girl Scouts movements are all about.
Since they were started during WWI or II(can't remember which) they did the same Scouty deeds all year round. Now, depending on which stream they are in some may do Computer and Math classes and others test endurance all in the hope of shaping good citizens.
The Army has been known to run endurance type classes for the young.There's an organisation trying to survive.
In the older Boy Scouts streams it is quite likely you find them sleeping in tents in weather below 25 degrees. The weather will not be a deterrent.
Is this not a discussion about sleeping in bags in cold weather ?

So out with the tent and sleeping bags again. And again I get in with all my clothes on. It got down to 25 and I suffered all night.

regards
[ October 28, 2003: Message edited by: HS Thomas ]

[Gail Schlentz]

Originally posted by Richard Hawkes:
I can't understand why you don't just get your man-servant to pump hot air into the tent with the bellows. I mean, they're going to be up all night keeping the fire alight anyway

Sounds like the best idea yet! Where do I find my man-servant?? Big-5??

[Timothy Chen Allen]

Originally posted by Richard Hawkes:
I can't understand why you don't just get your man-servant to pump hot air into the tent with the bellows. I mean, they're going to be up all night keeping the fire alight anyway

The BSA doesn't allow Man-Servants anymore.

[Richard Hawkes]

Originally posted by Elaine Micheals:
Sounds like the best idea yet! Where do I find my man-servant?? Big-5??
Try "Boys 'R Us"

[paul wheaton]

This is all about camping in the cold.
We will be doing two snow caving trips in January. At least one will feature snow shoeing too.
Plus there's the "Klondike Camporee" in early January. I think's it's held just a few miles south of Canada ("C", eh? "N", eh? "D", eh?). The warmest part of the day for these trips probably won't get above freezing.
So it seems to be wise to get a complete understanding of how to stay warm. I think there is great value to the anecdotal evidence. I want to try and get to the bottom of that with the scientific theories.
Currently, I think the keys are "cotton kills" and old people have a lower metabolism.
Wearing cotton that you have been wearing all day does have some moisture in it. With a small amount of moisture, cottom loses all of it's insulation value. In order to keep the external moisture warm, your body has to expend more heat than if the moisture was not there. Without any math, I would guess that if you wear jeans, a heavy cotton shirt and cotton socks, your body might need to generate twice as much heat to stay warm due to the small amount of moisture collected in these clothes.
(keep in mind, this is just my theory at this time)
If you wore no cotton and you wore your clothes to bed, you could have a light sleeping bag and be moderately warm. Your body is still attempting to heat some of the water in your non-cotton stuff, but the non-cotton stuff is also providing some insulation.
Based on what all I have read so far, it would seem that the answer here is to: A) bring no cotton; B) put clean clothes on just before bed; C) eat some carbohydrate just before bed to fuel your heat generators.
A bag liner is good, but a new bag liner each night would probably be wise.
One of Marilyn's posts talked about polar exlorers and how their sleeping bags weighed about 80 pounds when they got back. Some of the links also mentioned somthing about "no down!"
So, any holes in this analysis?

[paul wheaton]

This brings up another question: If cotton is out, what do you wear for pants in the winter?

[Jessica Sant]

Originally posted by Paul Wheaton:
This brings up another question: If cotton is out, what do you wear for pants in the winter?

Its all about layers.
Nice Bergelene or silk 1st layer -- wicks the sweat away from your skin
Fleece 2nd layer -- insulates and keeps you all warm
Wind proof / water proof outer layer -- keeps the elements out from screwing up those 1st two layers.

[paul wheaton]

This is my impression of materials so far - please correct me if I'm wrong (and tell me if I'm spot on!):
Cotton kills - when slightly damp, it has almost zero insulation value.
Wool looses insulation value when wet, but not quite as bad as cotton. While there are some expensive wools that don't itch, most wools do itch. Wool is also, generally, quite heavy - not optimal for backpacking.
Down (feather down) is lightweight, but does not insulate when wet.
Silk is light, wicks moisure away from you, is light, and dries quickly. Silk is the best choice for sleeping bag liners and long underwear.
"Fleece" usually means a fluffed form of polyester. Lightweight, warm and feels feels nice on the skin.
It sounds like synthetics are the best for everything but sleeping bag liners and long underwear - that's where silk is the best.
Am I on track?

[Dave Vick]

One thing you ahven't mentioned is some sort of ground insulating pad. That is more important than you would think, especially when you look at how much heat we lose through direct contact with the ground.
Another important point is foot care!!! Bring plenty of socks, bring enough socks to change at least 2 or 3 times each day. Bring enough socks so that you can loan 2 or 3 pairs a day to your neighbors who forgot socks. I assume you'll be fairly active so your feet are going to sweat a lot (depending on what kind of boot you're wearing, it could be a whole lot). Layers work well for socks too, a thin set of silk or polypro liners, then a thicker pair of wool. Need to change them very often becuase if you dont and you stop moving then your feet will quickly chill and make you miserable. Bring safety pins and clip the wet pairs to you fleece or polypro insulating layer so they dry as you move around. Keeps your feet from getting chilly and also avoids some possible foot problems from the prolonged exposure to cold and wet.
Other wise camping in the winter is great. I love it at night, when it is real quiet, and the sky is so clear, the snow and the ice particles sparkling, just sit back with a cup of coffee..... truely awesome!!!

[Jessica Sant]

Originally posted by Dave Vick:
One thing you ahven't mentioned is some sort of ground insulating pad. That is more important than you would think, especially when you look at how much heat we lose through direct contact with the ground.

Give me some credit Dave! -- check out my 1st post in this thread -- all about the joys of a sleeping pad.

[paul wheaton]

Dave, the logic behind the sleeping pad is clear to me. The thing I was having trouble wrapping my head around was the "don't wear your day clothes to bed because that will make you colder than if you sleep naked."
My impression is that this statement can be true if you wear cotton. False if you wear almost anything but cotton.
I'm thinking that one could have silk long johns and fleece pants/shirt on all day and wear that to bed and you'll be toasty. Of course, you might be taking some day time funkiness to bed with you, but that's a different matter.
A little clarity on wool: wool will continue to insulate even when wet. Wool will also do well next to a fire - if an ember lands on your pants, it will be fine.
And that's where synthetics have a problem. An ember from the fire lands on your fleece and it burns a hole.

[Gail Schlentz]

Originally posted by Paul Wheaton:
This is all about camping in the cold.

Ok. Here's my secret - when I'm camping with my family (not with the Girl Scouts), in order to stay warm at night, we ALWAYS make sure to turn the thermostat in the motorhome up to a toasty 72 degrees.

[Richard Hawkes]

Originally posted by Paul Wheaton:
Dave, the logic behind the sleeping pad is clear to me. The thing I was having trouble wrapping my head around was the "don't wear your day clothes to bed because that will make you colder than if you sleep naked."
Do you have a friend in the meat or frozen food industry? Might be time to experiment with their freezer after jogging in the park

[Marilyn de Queiroz]

Do they make sleeping bags of GoreTex (the ski suit synthetic)?

[Dave Vick]

Originally posted by Marilyn de Queiroz:
Do they make sleeping bags of GoreTex (the ski suit synthetic)?

They GoreTex outer bags for your sleeping bag. Kind of like a rain suit for your sleeping bag, they are great too. Add another 10 or degrees of warmth to your sleeping bag system. And keep you dry!!

[paul wheaton]

I don't need a buddy that works with a freezer. Temp outside right now is 20 degrees.
Trick or treaters are gonna be chilly this eve!
It sounds like I have gotten to the bottom of this mystery. The only issue left has to do with how synthetics can build up body stink in a hurry.

[Marilyn de Queiroz]

We've had a constant freezing drizzle in Denver since yesterday morning (24-27° F).