/ Calories & the cold

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Flinticus - on 26 Feb 2013
If camping out in the cold, should I eat before going to sleep as I assume the body will burn extra calories to generate heat?
andic - on 26 Feb 2013
In reply to Flinticus:

I think the half pound of hot rice pudding glowing away in your tummy warms you up just by being there tbh!

Unless you are shivering like a shitting dog all night do you really need the calories?
Flinticus - on 26 Feb 2013
In reply to Flinticus:
Well, I don't have much body fat and was camping high up in Scotland Sunday night: was a tad cold (despite ME winter down bag, good thick mat & clothing layers etc), not freezing but could have done with a few degrees more. After a few hours awake I ate most of a Soreen loaf, then actually got warm & had to take a layer off. Woke up later, a bit chill again & wondered if my body had burned up the loaf.
girlymonkey - on 26 Feb 2013
In reply to Flinticus:
Yep, eating will help, how much though I'm not sure. However I have noticed with a down bag I get chilly if I wear too much clothing! Your body heat has to get into the down to heat up the bag. On a very cold night I will wear base layers, as heat transfers well with these so they help, but if I am wearing thick layers that don't allow much body heat out then I find I get colder. Maybe it's just me, but worth a try!
Flinticus - on 26 Feb 2013
In reply to girlymonkey:
Found this list on the net: http://www.chiff.com/a/camping-sleep-warm.htm

I was probably under hydrated as well as I was rationing my water: no stove to melt snow and too cold for any running water (from about 300m anything potable was frozen solid).

I wore Paramo cascada trousers unzipped on my legs which seemed fine. However I could probably have done with a fresh thermal top.
Chris Harris - on 26 Feb 2013
In reply to Flinticus:
There is also the suggestion that blood is preferntially diverted to the digestive system after eating, so less to extremities, so colder toes.....
Flinticus - on 26 Feb 2013
In reply to Flinticus:
Again, more net research has thrown up:

"Strip off your layers of clothing to what will be appropriate in your sleeping bag. The more layers you wear the better insulated and the warmer you will be (contrary to the myth that says sleep in your underwear). However, too much clothing can compress dead air space in the bag and reduce its effectiveness."

Just about every site now visited recommends eating before going to bed & having a quick snack )of protein) if you wake up at night, e.g. from same site ( http://www.princeton.edu/~oa/winter/wintcamp.shtml ) as above

"If you wake in the middle of the night and are cold (or just before you go off to sleep) it is best to eat proteins. The protein will be broken down more slowly so the heat will be released over a longer period of time. If you eat a sugar, you will get a quick "heat high" and then your body temperature will drop back down, sometimes falling below its previous level"
TheDrunkenBakers - on 26 Feb 2013
In reply to Flinticus:
> (In reply to Flinticus)
> Again, more net research has thrown up:
>
> "Strip off your layers of clothing to what will be appropriate in your sleeping bag. The more layers you wear the better insulated and the warmer you will be (contrary to the myth that says sleep in your underwear). However, too much clothing can compress dead air space in the bag and reduce its effectiveness."
>
> Just about every site now visited recommends eating before going to bed & having a quick snack )of protein) if you wake up at night, e.g. from same site ( http://www.princeton.edu/~oa/winter/wintcamp.shtml ) as above
>
> "If you wake in the middle of the night and are cold (or just before you go off to sleep) it is best to eat proteins. The protein will be broken down more slowly so the heat will be released over a longer period of time. If you eat a sugar, you will get a quick "heat high" and then your body temperature will drop back down, sometimes falling below its previous level"

Makes sense.

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ice.solo - on 02 Mar 2013
In reply to Flinticus:

i seem to spend a lot of nights in tents in the cold (sub-zero, usually well below) and this is what i find:

undoubtably a hot meal full of fat and carbohydrates warms you up before sleep. eaten when actually in the sleeping bag optimizes this. for me at least, this flood of warmth lasts till about 3am when the body is at low ebb, sometimes waking from the cold. simply eating a few mouthfuls of chocolate or a cliff bar - plus the moving about to do - kicks the body into producing heat again.

staying warm isnt just about trapping body heat, its largely about minimizing loss to moisture (condensation in a tent and moisture off the body/clothes).
to this end, sleeping in minimal clothing works better as you are heating the sleeping bag - not your clothing - which then pushes moisture outwards. a cool sleeping bag just gets damper as time goes on.

indeed, the best system ive found is combining a down inner bag with a synthetic outer one which deals with the moisture. i either sleep in just a baselayer, or open big vents in my clothes to let body heat into the down. any insulating clothing goes between the 2 bags where it can dry, with the moisture moving outwards inthe the synthetic layer.

in the same way a mitt is warmer than a glove, a warm body is warmer in a bag than in a down suit (its also lighter to carry).
the idea of wearing down layers inside a sleeping bag only works when moisture is not a factor (smacking of lab tests but not the real world, certainly not over several nights).
if that were the go tho, then a synthetic bag over the down suit would boost the warming properties a lot, allowing the down to release moisture by putting the condensation point beyond it, rather than inside, somewhere in the synthetic where its less problem.

but anyway, kcals before sleep - definitely. and actually in a tent in winter its hard not too as short days mean youre inside with not much do besides eat fairly early anyway.
for that 3am warmth top up, a gel inside a sleeve is good - keeping it in a pocket can lead to bursting it open if you roll onto it - something ive learned the hard way.

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