Concepts of keeping warm in cold conditions: how to hike in the cold using the layering system.
Winter is coming
Where the layering system excels is when operating in extremely cold conditions. Im not joking around either I am talking about Siberian 50 below snowing weather. In this case, easily changeable, high quality, and extensive layering will be crucial, but more importantly is how you cover your body.
Dressing for extreme weather starts with the layering. If you haven't read our layering guide then stop here and read it before proceeding, this article we will only summarize layering.
Layering is made up of three... layers of clothing. The first which is closest to your body is the base layer, the insulating layer in the middle, and the outer layer between the other layers and the environment. These layers are often referred to as the wicking layer, thermal layer, and shell layer, respectively.
The advantage of layering is the layers can be changed in and out as conditions change. Each layer (base, thermal, or shell) can have its own layers. For example, wearing multiple thermal layers to help keep warm or wearing light and easily changeable smaller layers to adapt to the situation.
Each layer has an important role in keeping the body warm. The base layer wicks away sweat keeping the body cool and helping the clothing to dry quickly. The thermal layer is strictly for keeping warm by trapping air between its materials to provide powerful insulation. The shell layer protects the body and all the other layers from the elements while letting humidity escape through the material.
The layers get these “super powers” from the materials that make up the clothing. Since we covered this extensively in the Layering Guide, we wont mention more.
There are three places you want to make sure you are keeping warm; appendages, core, and your arteries.
The core houses the most vital organs in the body, so you can see why it would be important to keep warm. The body cares about these organs, so much so, it will actively pool blood in the core when the body gets cold. This strategy of the body is to keep these organs ‘safe’. Its one of our bodies many defense mechanisms that sometimes might end up killing you.
Since the blood is being redirected to the core, there is less blood for the appendages. This makes the arms and legs numb, difficult, and even painful to operate. This can be dangerous when you need to build a fire, call for help, or get to shelter.
The constriction of blood vessels help conserve body heat but will also cause numbness in your hands and feet and sometimes pain as blood can not properly get to your muscles.
The appendages are important to keep warm as they are your everything for maneuvering, especially in an emergency. Not being able to feel your fingers or toes can be a life or death situation. These appendages are also more prone to frost bite which can lead to permanent damage to the body.
The pins and needle feeling one gets from going from a cold to hot environment is due to the unfreezing of small capillaries in the extremities.
Lastly, the arteries. Why would it be so important to keep the arteries warm? The major arteries are tunnels for large amounts of blood leading directly or indirectly to every part of your body. If this blood gets cold it will travel through your appendages and to your organs.
Just ask kangaroos which lick their wrists so that the evaporating moisture cools the blood running through their ulnar artery. Its impressive how not properly insulated legs or neck, areas that have very large arteries, can affect the core temperature.
There is a sort of heat triangle at play here where if one corner gets cold it may effect the others. Cold core pushes blood away from the appendages, appendages are key tools to keeping you alive but become less effective, appendages house large arteries which then push that cold blood to the core, core is cold again and your in risk of suffering hypothermia. Anyway you spin this, all three areas should be insulated properly.
Skin, eyes, and extremities
It is true that keeping appendages, core, and arteries insulated will help keep you properly warm but there is a few other places that should be kept covered; skin, eyes, and extremities.
The skin is the first area of contact to the cold and is quite sensitive. The skin can easily suffer from permanent damage. Long term exposure to wind can easily dry out the skin and help freeze the epidermis which will lead to frostbite. Keep skin covered from wind and in much colder environments under a thermal and base layer.
As you may already know, the eyes are also quite sensitive. In windy, cold, even snowy environments the eyes can get barraged by the cold and the cornea can freeze. If you find yourself without googles and it is painful to open your eyes then just leave them closed. Frozen corneas will impair vision and can be very painful. Usually this is a problem in more extreme conditions, such as hours of sking, climbing Everest, or a very cold, windy, and snowy day outside. If you can detect the symptoms or just be prepared for this event then you can prevent an inauspicious situation. If you know you will be in these conditions bring googles or a face mask.
Fingers and toes as well as other extremities are some of the most sensitive parts. Exposure to the cold can result in problems such as frostbite.
First degree frostbite, also called frost nip, can cause can cause temporary pain or skin numbness for as long as a few months.
Second degree frostbite is more than superficial and can cause blisters that may dry, blacken, and peel away skin.
At the Third degree not only has the skin been damaged but so has the tissue underneath. The skin will become blue-grey and crusty. At this point long term damage has occurred and if untreated can result in loss of appendages, serious infection, and even spreading to the rest of the appendage.
During fourth degree frostbite,i muscle, tendons and even bone have been effected. Early symptoms can include rewarming of the skin, lack of pain in effected area, and loss of color of the skin with later symptoms including black and mummified skin. During this stage Autoamputation could occur.
The most effective way to keep warm is to create a thermal shield around the entire body. Leave nothing to the elements if possible. In extreme cold you will need to keep the skin, face, and even eyes, completely covered. Again, this is where the layering system comes into play. The base and mid layer will help enact a thermal shield while the outer layer will keep the elements off the skin and layers.
There is more to understand when keeping warm. Due to the length of the original article we broke it up into two. The second will deal with how to dress. Stay connected...