Keeping warm in a sleeping bag

[r0ssrg]

Hi all

We have -5 Mountain Design sleeping bags and I was still cold when it was only forecast to be +3.  I've heard I shouldn't be wearing too many jumpers to bed as I wouldn't be giving off enough heat for the sleeping bag to work properly.

Is this true?

What does everyone else do that goes camping in winter?  I need to get this sorted before we leave next year.

Rossco

[Tim - Stratford]

Rossco,

Make sure you're on a good insulated layer - most of the cold seeps through from below. In my swag I have an old 'blue' $5 close cell foam mat under my swag matress to insulate from the cold. In the kamper we have woollen underlays.

With a good sleeping bag it is also important to use a liner. This adds warmth but more importantly keeps the sleeping bag cleaner so stops the fill getting dirty and unable to trap air.

Lastly thermal pants and t-shirt, and if below 0c - a beanie - provides warmth without being bulky and uncomfortable.

Tim

[morcon]

I have a -5 Black Wolf and use it in my swag; I find it good but I would probably wear a tracksuit as well if it was getting down around zero. A beanie and socks are good when it is getting really cold. One of my kids used my sleeping bag on their camp stretcher and they got cold in it but by putting a blanket under the bag they were warm.

[D4D]

Make sure you're on a good insulated layer - most of the cold seeps through from below. In my swag I have an old 'blue' $5 close cell foam mat under my swag matress to insulate from the cold.

That's a good idea, thanks!

[austastar]

Hi,
   a 'warm' sleeping bag will have good quality down, and be box stitched with walls so that the down fill is held in place and there are no stitches that pass from inside the bag to the outer layer.
A zip draught excluder will keep things warmer, and some of the new bags are now fitted with an internal collar to prevent draughts if the top is not pulled tight.
As mentioned above, beanies are good if the hair is thinning a bit, a lot of heat can be lost from the head, and insulation with a thermal mat underneath is a must, if on a canvas stretcher or on cold damp ground (especially snow).
cheers

[BigJules]

I don't like wearing clothing to bed, especially in a sleeping bag. We went camping on Friday night and I was surprised to find myself quite cold, although it was snowing nearby. I take a silk sleeping bag liner with me, which adds 5-10 degrees of eating IMO. Unfortunately that was in the back seat and I wasn't getting out of the swag to find it.

[Mace]

Just remember in principal that heat flows from hot/warm areas to cold areas (second law of thermodynamics).  We loose heat by various means:

Radiation into the surrounding atmosphere
Conduction into an adjoining mass
Convection is another means of heat transfer, due to fluid motion.

By putting something between you and a nearby cold mass  you are creating a barrier that keeps the heat generated by your body from moving away via radiation or convection,  - so i feel nice and snug in my sleeping bag if  i put  on a beanie as it stops radiation loss from my solar  panel!,

By putting a thermal blanket or some other barrier between myself and the bed base (in addition to the mattress) , I am preventing conductive heat loss.  Various things can do this, silver thermal blanket, thermal mat, etc.  Egg shell underlays are also good, because they create voids or pockets in which small warm air masses can exist.  These slow the conductive losses down.  FLanalette sheets help a lot also becasue of this.

Im usually that warm in the CT Bed that I just wear boxer shorts and a beanie, sometimes soxs and a t-shirt.  SHMBO radiates heat like a furnace that I usually have to put a foot out the side of the bed to keep cool!! 

[Matto]

Also, keep in mind that the rating of a sleeping bag is a guide to what temp it will keep you alive in. Ie, a -5 bag may be enough to keep you alive at -5, but you won't be getting a good nights sleep - you'll still be cold.

+1 to everything everyone's already said, especially the insulating layer underneath. I spent a night recently in my sleeping bag, on a cross-leg stretcher. Man was it cold! I didn't get much sleep - you could feel the air pulling the heat out of you from below.

Good luck!
Matto

[baldheadedgit]

My old sleeping bag is about 30 years old,, (no, not that one, she's a lot older.!)   good down to - a lot,,,,, but i sleep on a strecher bed with another sleeping bag beneath it to insulate,, that makes all the diff,,, and i love me beanie when its real cold.


BHG

[SUPA105]

In addition to our winter sleeping bags in our swags we keep a folded First Aid space blanket if required during the night to drap over the top and a daily telegraph to spread out in the swag under the mattress before jumping in........wear out thermals and beanies aswell.......as its been said  "insulation", keep the heat your making in with you and the cold out.

Coldest night spent in our swags so far was -8 in still air with a big frost that stayed on the ground ALL day in the shade......the kids went for the space blankets and where to hot.....we adults took our insulation internally before bed.....

Cheers

[Buccan80]

When I was living in UK I was in venture scouts and we were always told to keep a set of thermals only for sleeping in as if you jump into your sleeping bag with clothes you have been wearing for a while they keep some of the moisture from sweat and this will cause you to get cold through the night especially socks.

[rodw]

What's wrong with a rum blanket?   

[r0ssrg]

Thanks Team

I was sleeping in the CT, on the foam mattress with a egg shell foam mattress on top, a sheet and then the sleeping bag.  I was cold.

The kids had a stretcher, a roll up self inflatable 5cm foam mattress, an army blanket doubled up, sheet, -5 sleeping bag and their old +5 sleeping bag draped over the top.  Thermals, tracksuit and jacket and apparently were warm enough.  They did complain if the +5 bag fell off during the night.

I have been speaking to a mate from Wales and he recommends the thermal survival blankets if you can stand the heat.

I said that sounds good to me!!!    Although worried it will fall off as I turn in my sleep.

Any other ideas?

-5 sleeping bag placed inside the +5 sleeping bag.  Just pray you don't have to go to the toilet.

Rossco

[JCOJ]

If you do have a down sleeping bag, make sure you give it a fluff before jumping into bed.  The biggest factor for down is what's called loft - the bigger the loft the warmer it is.  By fluffing the bag before getting into it you are causing the down to loft.  Also good protection from below is paramount.  Exped campoing matresses are the best for this - they are expensive, but once you sleep on one you won't go back. 

[corynmelnkids]

A half a carton before bedtime usually keeps me warm.
But on a serious not the missus and i went camping on the weekend got down around 5 i believe all we had on was a sheet and sleeping bag opened up. I had shorts and a shirt on and was warm the missus
a shirt and a jumper long pants and socks and complained the next morning about how cold it was. So i think it is all a personal thing every one is different.

[macca]

Aggree with all the comments on the cold coming from below, I've had the same sleeping bag for years and used to struggle with the cold, then I got a Thermarest inflatable mat and rarely have to do the sleeping bag up anymore.

[austastar]

Hi,
   now this would keep you warm on the coldest of nights!





More details on the Stevensons Warmlite bags here

I bought one of their expedition tents many years ago, it was bomb proof, but WAY too serious for relatively warm Tasmanian winters. Their stuff is designed for Alaskan conditions.

cheers

[Garry H]

good down sleeping bags should be stored not all scrunched up in the travelling bag, but fluffed loose, the rating on the bag will mean even less (or nothing) if it's not stored right between trips.
we both have top end Kathmandu bags, only paid around the $300 mark instead of the normal 8-900, couldn't be more happy, always use a liner as well
oh- and a couple of large glasses of port help with the sleep as well (but not the snoring they tell me!)

[LB]

We have used the same Blackwolf sleep bag for the past 10 years and have never been cold. When we used to use one of those velour blow up type mattress we put an old sleeping bag between our bag and the mattress. Now have the blackwolf self inflating mats and the cold no longer comes up.

LB

Stick a hot water bottle in before you go to bed and scotch always works.

[Matto]

now this would keep you warm on the coldest of nights!

Needs ta get me one of them! Buy now... buy now... buy now...

Cheers!
Matto

[Matto]

A half a carton before bedtime usually keeps me warm.

Which is all fine and good, until you need to get up at 1am to drain the remnants of said half carton. I find that trip usually removes any heat I've managed to build up in one easy step. Of course, if you have a special system to deal with this, I'd really love to hear about it! (first step, get 6m of garden hose...)

Cheers!
Matto

[xcvator]

Stick a hot water bottle in before you go to bed and scotch always works.

Ok, why would you put scotch in hot water bottle ? Me, I'd rather drink it

[Hefty]

Another thing that really helps (though it's not always practical/possible) is to make sure you're warm before you get in the bag!!
We need to remember that technically it's not the "cold getting in", it's the heat getting out.
If you're camping with a fire, after you've done your chosen bedtime routine, spend a few minutes nice and close (not too close if you've had that half a carton ) to the fire and then get to your bed and into the bag before you lose the heat.
Otherwise, yes a hot water bottle is good too if you have one.

Cheers!
Jono.

[6knights]

I read somewhere that the silver/blue sarking that they use on house wall will also keep the cold out if placed under your bedding

[austastar]

Hi,
    facing a seriously wet/windy night in a crowded hike tent years ago, I had the brilliant <not> idea to stop my feet/legs getting wet against the edge of the tent by putting the foot end of my sleeping bag into a spare plastic garbage bag.


Error!


The bag ended up wringing wet with condensation on the inside of the plastic.


I'm not sure what the blue/silver sarking would do under the bag, but if it was under the sleeping mat where the hot/cold difference for either side would be minimal it should be ok.


cheers