Operating in the cold

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Operating in the cold

Message par savage » 21 Juin 2005, 21:51

ceci est un copier/coller d'un texte troouvé sur un forum US. c'est le meme theme que mon dossier "s'entrainer en milieu difficile", mais axé surtout sur le froid (c'est pas la saison, mais ça sera utile pour cet hiver)

pour le moment y a pas de traduction de prevue.


I know that this is probably not the most appropriate season to post this however it's cold somewhere in the world. I have had the great displeasure of operating in some pretty frigid environments (as low as -60 degrees C) for the better part of my life and have taken for granted the knowledge that I was taught and grew up with. After meeting many people from more southern regions of the globe who have not been exposed to temperatures like these before I figured I would compile an information package for some of you who may very well end up in a situation that could require it. It's a little long winded but if a saves someones toes frome freezing off it's worth it. This stuff is especially important for guys that may have to lay stationary for long periods of time (Perhaps one or two like that on here ). Here goes:

Body heat can be lost in any of the following ways:
(a) immersion of body parts e.g. the hands and feet (or the entire body) in cool or cold liquids so keep yourself dry, if you must lay or sit for a period of time beware of snow that will melt due to your escaping body heat;
(b) direct contact with cold surfaces e.g. the ground, tools, machinery, products being handled. Try to keep a barrier between yourself and the ground, don’t touch cold objects (i.e. rifle until necessary);
(c) conduction of heat through wet or damp clothing, including clothing damp with perspiration;
(d) exposure to cold air, including inhaled and exhaled cold air. There are several face and head protecting devices that will help in this area, however beware that if eyewear is worn these things can cause the eyewear to fog or ice over very rapidly;
(e) evaporation of sweat (don’t keep yourself too warm or you will regret it); and
(f) consumption of cold liquids or foods.

The body maintains heat balance in two main ways:
(1) Restricting blood flow – the body automatically reduces the amount of blood circulating through the skin and cooled body parts by constricting blood vessels supplying blood to those regions. By doing so, warm blood is diverted to the body’s core, maintaining the temperature of internal organs and the brain.
(2) Shivering - this can temporarily raise your body temperature. Slight to moderate shivering is not uncomfortable and will warm you (this will however effect shooting and can easily degrade into more severe shivering). Severe, uncontrolled shivering occurs when body temperature falls to 35 degrees C (normal body temperature is 37 degrees C). During severe shivering, body heat production can rise to as high as 4 to 5 times normal. Severe shivering is a sign of danger and a severely shivering person should be immediately removed from exposure to the cold.

Measures to prevent cold injuries:
a) Diet
You have increased energy requirements when working in the cold. Consider adding additional wholesome foods to the diet such as pasta, potatoes, rice, dairy products, nuts, meat, herring, and salmon. Light snacks and warm fluids should be taken during rest breaks. Alcohol must not be consumed when working in the cold. Alcohol produces a deceptive feeling of warmth but may contribute to dehydration and impair judgement.

b)Dressing for the Cold
To stay warm in the cold:
(1) clothes must be layered to manage moisture and keep dry,
(2) insulating layers must trap air to stay warm, and
(3) you must be protected from the wind and weather.

To remain comfortable as weather and work conditions change, clothing layers should be added or removed, or ventilation openings in clothing opened or closed to remain comfortable. Clothing layers should be managed to remain comfortably warm. Every effort must be made to avoid sweating and becoming damp. Clothing selections are normally made on the basis of staying warm while inactive. Consider the task to be performed and the weather conditions, then dress so that layers can be shed and they can still remain comfortably warm. If clothing layers do become damp and remain that way, you should be prepared to replace them before becoming chilled and hypothermic. If you are sweating, then your clothing is probably too warm for the conditions and tasks being performed.

The following approach of using three clothing layers – inner, middle and outer – is applicable to all situations. However, the recommended synthetic fabrics may not be appropriate for situations requiring clothing with fire resistant (FR) or anti-static properties. FR clothing next to the skin must be made of non-melting natural fibers such as wool or silk or an acceptable fire retardant material. The general practices described below should be followed, recognizing that the fabrics selected may be limited by specific, special applications.

*A quick note on wool. Wool is perhaps the best material to wear when there is the potential to get wet. Due to properties inherent in wool it will actually maintain a great deal of warmth when wet. Dry is best but if you’re going to get wet remember wool.

Inner Layer
The first layer of clothing should manage moisture by moving perspiration away from the skin to keep you dry and comfortable. Avoid cotton, especially in long underwear and socks. Once cotton is wet, whether through perspiration, rain, or snow, it loses all insulating properties. For long underwear, brands made of synthetic fibers (e.g. polyester, polypropylene, etc.), silk, or wool retain body heat when wet and wick perspiration to outer clothing layers for evaporation, leaving the body dry. Many types of long underwear are available in varying thickness or weights depending upon intended activity level and weather conditions. Select an appropriate style and thickness of long underwear.

Middle Layer
The second or middle layer(s) should trap warm air escaping from the body and hold it in open spaces within the layer(s) to keep the worker warm and insulated. You should wear several thin layers of clothing rather than one heavy garment. Layers can be added or removed, depending upon weather and activity level. Select lightweight clothing that provides freedom of movement. Multiple middle layers give you the ability to tailor their need for warmth based on environmental temperature and activity level. Look for middle layers that can be added or removed easily. Zippered neck openings and zippered leggings allow for ventilation. A down vest or jacket may be an appropriate middle layer.

Outer Layer
The outer layer should provide protection from wind, rain, sleet and snow. It should also keep cold air and moisture from penetrating into the middle layer(s). Breathable fabrics may or may not be necessary. Wind resistance is a critical feature of an outer layer used in the cold outdoors. Two-way zippered front openings can be used to regulate heat load and ventilate the body. An outer layer having arm-pit zippers can be helpful in providing ventilation. Windproof pants or “wind pants”, fully zippered from ankle to hip, can be added or removed without footwear having to be removed. Jackets with hoods offer an additional layer of protection for the head. Newer hood designs provide unimpeded views and free movement. Cotton twill made water and windproof may be an alternative. The extremities must also be protected. The following suggestions apply to the hands, head and feet.

Handwear
Mittens keep hands warmer than gloves since fingers are together. With gloves, fingers are separated, losing heat from one another. Wear thin glove liners under gloves or mittens. If you need to remove the mitts to use equipment liners need not be removed when removing the gloves. Removable glove and mitten liners can be replaced and dried when they become damp. New mitten styles include three-finger “lobster claws” which keep fingers warm yet offer good dexterity. Windproof overmitts offer additional hand protection without adding significant bulk.

Headwear
Up to 50 percent of body heat is lost through the head. A hat or other head protection must be worn in the cold. Avoid cotton and use synthetic fabrics or wool instead. Select a hat appropriate for the weather conditions and activity level. Consider thickness, extent of head coverage (e.g. open-faced or full balaclava, ear coverage, etc.), need for wind resistance, effect on vision and hearing, and ability to fit into or over protective headwear if required. A facemask and eye protection may be necessary under some circumstances.

Footwear
Warm, insulated footwear is essential. Boots should have thick soles for insulation while standing in snow or on cold concrete. Footwear selection should be based on the work being performed, the surfaces on which the worker will work, and the weather conditions to which the worker will normally be exposed. Tight-fitting boots reduce circulation and can make feet feel cold. Footwear should be sized so that it will accommodate an extra layer(s) of socks. A synthetic sock liner worn beneath a synthetic blend or wool outer sock wicks moisture away from the skin, keeping feet drier and warmer. Waterproof boots (e.g. gore-tex, etc..) is one of the most effective means of keeping feet warm when working in the snow. Inadequately insulated or sealed boots will allow snow to melt on the boot and water will seep in soaking your feet, and in short order your feet will be near frozen.

Often Neglected Body Parts
Most people when faced with operating in the cold will immediately put on a warm jacket, thick socks, hat, and gloves. If you are faced with spending a long period of time in the cold or must remain inactive while exposed this will not be enough. The legs, neck, and face/ears must be effectively covered to maintain any level of comfort in extreme cold conditions. If you cover these areas using the suggestions above your ability to stay on station will be greatly increased.

Wind chill
Wind chill is a killer, it can turn a bearable day into a frozen nightmare. Avoid moderate to high wind if possible, even if it means digging into snow to do so. Ensure your outerwear is windproof as suggested above, and make sure to cover any exposed skin. When faced with high winds and cold temperatures skin can freeze in minutes.

Judging your heat transmission
A quick way to tell how effective your clothing is on a cold day is observe snow on your body. If snowflakes melt when they land on your clothes, boots, hat, etc.., this means that you are losing body heat through your clothes. If however snowflakes remain frozen your body heat is being trapped inside and is not readily escaping. Use good judgement when applying this method as it may lead to false conclusions if the weather is warm, extremely cold or you are working hard and generating an elevated level of heat.

Adapt your body
The human body adapts itself to the environment very rapidly. If you know you will be operating in an area much colder (or warmer for that matter) than you are used to you may want to prepare before you go. Try to expose yourself to cooler than normal temperatures, meat lockers, cool nights, wading in cool water, these things and many more can help acclimatize your body to cold temperatures. So throw on some light clothes and get cold. Most people avoid cold at all costs however if you are acclimatized to it the discomfort is minimized, amount of clothing required to maintain function is reduced, and your time on station is greatly increased. *Do not expose yourself to a degree that will cause you harm, you are just trying to push the comfort barrier.

These tips are by no means a substitute for arctic survival training, however if applied properly they can save your life.

I hope this helps somebody somewhere because it took a long time to type. If not thanks for reading.
savage
 
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Message par comanche » 22 Juin 2005, 01:07

Je trouve cela très intéressant car au Canada, le froid, ca nous connait! PDT_Armataz_02_02 en passant, quel est l'adresse de ce site ? Il a l'air très pertinent.

Merci!
comanche
 

ya aint go like dat

Message par glock » 26 Juin 2005, 11:02

savage, pourquoi tu nous traduit pas çà bordel!!!
yen a plein jsui sur qui repondront!!!
glock
 

Message par comanche » 26 Juin 2005, 15:56

glock> http://www.reverso.com
Ce n'est pas parfait mais pour ceux qui ne se forcent pas à traduire... PDT_Armataz_02_05 PDT_Armataz_02_11
comanche
 

Message par ade » 18 Oct 2005, 14:32

je sais pa lire l english
ade
 

Message par savage » 18 Oct 2005, 14:41

fallait bosser l'anglais à l'ecole!
peut etre que quelqu'un traduira

en attendant, tu as ça:
http://forcesspeciales.free.fr/phpBB2/v ... .php?t=244

et ça parle de differents milieux, pas seulement le froid
savage
 
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Re: ya aint go like dat

Message par {mat} » 18 Oct 2005, 19:48

glock a écrit :savage, pourquoi tu nous traduit pas çà bordel!!!
yen a plein jsui sur qui repondront!!!


tu pourrais être poli et demander gentillement à Savage qui passe énormément de temps à nous concocter des dossiers hyper intéressants.
{mat}
 
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Message par Sotek » 25 Oct 2005, 17:47

Encore un post technique intéressant de Savage.
Sotek
 
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Re: ya aint go like dat

Message par raid » 11 Déc 2006, 16:01

{mat} a écrit :
glock a écrit :savage, pourquoi tu nous traduit pas çà bordel!!!
yen a plein jsui sur qui repondront!!!


tu pourrais être poli et demander gentillement à Savage qui passe énormément de temps à nous concocter des dossiers hyper intéressants.

tout à fait vrai PDT_Armataz_02_02
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raid
 
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Message par sissit » 11 Déc 2006, 20:12

c'est vrai que ca fait super long a traduire quand meme, mais avec qq notions et un dico anglais francais tout le monde peu y arriver PDT_Armataz_02_02
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