and what sould I pay attention to?
Hi Mari, in addition to the good advice of others, I would like to underline the importance of understanding the clothing system, to give a little idea of the thing in practice, a small video:
Then, according to David Manise and Julien Imbert in their life/survival manual, great cold, the purpose of the clothing system, which is the first bulwark against the cold and other elements, is for:
-To evacuate the humidity produced by the skin: the phenomenon of perspiration
And of course in case of physical activity transpiration.
The evaporation of this moisture to the outside is important in the clothing system.
Materials made of merino wool, for example, wick away this moisture while retaining their insulating properties.
-Keeping warm, stabilised air close to the body: down/duvet, polyester fleece etc. create a pore volume, where the air is both warmed and mobile, which produces this insulating layer.
-Protect the insulating layers from wind and external moisture: in the clothing system this is the outer shell, it must be waterproof, windproof and breathable at the same time.
"By understanding the purpose and limitations of each layer of the clothing system, one can easily adapt one's outfit to the various situations encountered in winter nature.
Layers can be removed or added as needed throughout the day, in a precise and meticulous manner to both manage your temperature and protect your clothing from moisture.
The aim is to stay dry and 'comfortably cold' during activity and 'dry and warm' during rest and inactivity".
So the addition or removal of layers of clothing will depend on :
-Level of activity
-Air temperature
-The presence of wind
-rain/snow contact...
A small note on the importance of the hat/beanie and scarf to keep warm, because on average we lose 20% of our warmth on it.
Perspiration - Wikipedia
In the same order of ideas:
To wick away moisture, cotton is not very good, it's true, it has a tendency to absorb it, it's even hydrophilic.
In order to avoid spinning bad cotton, this property can be put to good use in a specific context, e.g. during intense activity, wearing a cotton T-shirt, taking it off immediately after a break and replacing it with technical underwear, thus wicking moisture away from the clothing system immediately.
Also put a cotton scarf in the sleeping bag to absorb moisture from the environment.
The disadvantage is that the cotton needs to be dried somewhere.
I would also like to add the importance of breathing in the cold environment.
Our breathing in the extreme cold, where the air is very dry, dehydrates us enormously. In order to minimise this loss of liquid, it is advisable to breathe only through the nose, because unlike our mouth, which vaporises, our nose allows us to recover some moisture.
Another thing for dehydration in the extreme cold is to understand the couple of cooling and warming.
Cooling: contraction of peripheral blood vessels
>>>> Increase in blood pressure
>>>> Urine production to reduce blood pressure.
Warming up: Re-dilation of peripheral blood vessels
>>> Lowering of blood pressure
>>> Water intake to restore normal blood pressure
While taking a look at this thread, I came across this post of
AzarHyun:
Does anyone have any plans for the coming Ice Age?
that led me to this one by
Laura:
Kantek
which echoed the latter:
Human body temperature has decreased in United States, study finds
And finally this video in French, subtitled in English to put which started off rather well, with some interesting connections on the decrease of body heat, with viruses... But ended up on the global warming of the centric body: