Friday, October 15, 2010

Three-Layer System

      A layer system does not seem like a new concept to us, considering that we dress in layers all the time.  The effective ideas behind the three-layer system are simple in nature, but a bit different then what we’re used to.  Practiced by woodsman, campers, skiers, and survivalists for centuries, it is by far the most effective way to dress for any and all outdoor excursions.  Knowledge of this system can keep you comfortable in any and all climates whether indoors or out.   It can also protect you from the elements like wind, rain and the sun. 

     The secret to being comfortable all day long in our ever changing climates, is in the way you regulate your body’s temperature by building a microclimate through proper use of your clothing.  Three different, multi-purpose layers all working together with your body's natural temperature.  The climate outside determine the fabric for each layer, or if that layer is needed.  The main and most important reason, other than comfort, for the layers are to stay dry, especially in colder climates. 

     To stay dry, you want to constantly pay attention to how much your body heats up due to activities, shedding clothes the more active and sweaty you get.  Try and always stay on the cool side avoiding sweat if at all possible.  A few ways to cool off and regulate your body temperature are to remove a hat, unzip a layer or two, drink water, or just take a small break.  If you start getting cold you can add another layer, zip up, drink hot liquids, or eat some food.  Food, especially high caloric foods, heat the body up because of the effort it takes to break it down in your system and is very similar to adding fuel to a fire, making it hotter.  In fact, the word “calorie” was first described as a unit of heat and later became a common term for a unit of food energy.

Base layer

      The base layer is the layer that is in direct contact with your skin.  It is your socks, underwear, liners, etc.  The main point of this layer, beyond keeping you a bit warmer in the winter, is to “wick” away moisture from your body.  Wicking is a fabrics ability to allow moisture to move away from your skin while dispersing it into the layers above or into the air.  It also allows the garment to dry much quicker than other non-wicking fabrics (like cotton).

      In the summer your layer should be lose and flowing, allowing the wind to dry the excess sweat, helping you stay a bit less constricted and comfortable.  Breathable, light fabrics that can wick large amounts of sweat are suggested.   I prefer my base layer in the summer to be made of fabrics like polyester, nylon, or Capiline because of their quick drying abilities.  I typically wear short sleeved shirts, but when I do wear long sleeves I make sure it’s a polyester blend so that when it does get wet, it dries quickly.  I do occasionally wear a cotton t-shirt during warm weather for comfort and ease.  I don’t wear cotton when I’m out of the apartment for an extended period of time, and I never ever wear it when camping, hiking, or for any activities in the bush.  The point of clothing in the hot summer months is to protect the skin by keeping the sun off the body.  Sunburn can lead to dehydration, and effect the body’s natural ability to cool itself through sweat.  Also make it a point to constantly drink water to help your body keep its core temperature regulated.

      For the colder winter months the base layer should be form fitting, not allowing the bodies heat to escape and dissipate into the air.  Warming fabrics such as wool or polypropylene can be used to add insulation to your base layer.   I suggest having a lightweight fabric base layer (such as polyester, ultra light merino wool, or Capiline) if, like me, you are always hot and sweating.   If it’s really cold, or you are prone to getting cold easily, (Women tend to get colder than men due to the fact that the blood vessels near the surface of their skin constrict sooner than men’s especially in the extremities.) wear a mid-weight fabric like something made of wool, or a wool blend with polyester (to help it dry quicker).  The base layer shirt should have a zipper at the neck to be unzipped when you are heated up by activities to help regulate the microclimate.  You should also have light to mid-weight long underwear bottoms depending on how hot you get normally, and how much activity you plan on doing.

      Make sure to keep yourself a bit cool to reduce the amount of sweat you produce by taking off or adding layers.  Sweating too much into your base layer during cold weather can make you wet which, if not taken care of immediately, can be very dangerous and potentially lead to hyperthermia.

Middle layer

      The middle layer, or mid-layer, is meant to insulate the body, by retaining the body’s heat, and continue with the moisture transfer initiated by the base layer to help you stay dry.  By slowing heat loss, and creating a dead air space around your body, you can stop the exchange of cold air and your body’s heat.  The thicker the fabric and more layers you add to your mid-layer determine how warm you can make yourself.
     In warmer climates you may decide to leave this layer home, but I suggest always carrying a basic long sleeve shirt.  Having a light weight, long sleeve, shirt made of polyester or cotton in the heat can help keep the sun of your skin, wick away sweat, and give you a little extra insulation if you end up getting chilled due to constantly going into air conditioned buildings and subway carts.

      For the cold weather, the mid-layer is what keeps you from staying cold and frigid in the harsh climate.  Wearing fabrics like wool or polypro are great for mid-layer items due to their abilities to keep you warm and dry.  You can play around with light weight and medium weight mid-layers to see which you prefer best.  As a rule of thumb, where light weight mid-layers when active (commuting on foot, hiking, biking) and medium to heavy weight when less active (waiting for bus, strolling through the park).  Try to get items that have zippers to allow you to vent and cool quickly and easily.   I like to wear multiple mid-layers such as a sweater and a light jacket to give me even more control of my clothing microclimate.

Outer layer

      The outer layer is your clothing’s shell. This “shell” shields you, and your clothing, from the elements like wind, rain, and snow.  It is the first line of defense, and is just as important as the other layers to let moisture from your body escape.

      In a warm climate, an outer shell can consist of a basic nylon rain coat or poncho to protect you from the wind and rain.  Wearing this shell when not getting wet can lead you to over-heating and is not suggested beyond protection.

      During the cold months of the year your outer layer is important to containing, and protecting your inner layers.  A Gore-Tex jacket, or something similar, will keep you from getting wet and allow the moisture from your body, and other layers, to evaporate into the air.  You can further your protection by also wearing nylon, or Gore-Tex pants if the forecast predicts precipitation on your travels.  The outer layer protects you from the wind in cold climates as well, which is of great importance.  Wind replaces the hot air your middle layer has trapped with cold air, and leaves you chilled to the bone.  Without this protective layer, wind and rain can leave you susceptible to hypothermia no matter how warm your base and middle layer have you.

     Here is a link to a YouTube video that does a good job explaining a typical cold weather trek layer system.


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