Dressing to survive in the outdoors starts with knowing what fabrics to wear. Different fabrics have radically different properties. Choosing the wrong type, or mixing clothing of different materials, can be disastrous!
You may not be able to tell what a garment is made of by looking. A nice, fuzzy, thick 100-percent cotton flannel shirt will be warm and cozy until it gets wet. Then that wet shirt may suck the heat out of your torso and cause hypothermia!
On the other side of the equation is wool. My hands-down favorite in the winter, wool, is generally a bad choice for a desert hike in August. Wool traps heat, and while it provides some UV protection, the material will prevent your body from cooling.
So, the buyer needs to beware.
Before buying any clothing item, read the labels and find out what the material is. Ignore fashion or what's trendy (I know that's hard – I have a 14-year-old daughter!), And make your purchase based on the activity and the clothing protection that will be needed.
Here are some common fabric choices:
* Cotton: Depending on where you live, cotton clothing can kill you. Cotton is hydrophilic, meaning it is no good at wicking moisture away from the skin, and can become damp just by being exposed to moisture.
Both of these 100% cotton garments would keep you warm until they got wet. Then, this clothing could become dangerous to wear!
Once wet, cotton feels cold and can lose up to 90 percent of its insulating properties. Wet cotton can wick heat from your body 25 times faster than when it's dry.
Since I've spent a lot of time in the Deep South, my favorite hot weather shirt is a medium-weight, white, 100 percent cotton Navy surplus shirt. The shirt has a collar that can be pulled up to shade my neck, and pockets with flaps and buttons. Cotton also has a reasonable amount of UV protection.
On really hot days in a canoe, a cotton shirt can be soaked with water, and worn to cool you down. On a desert hike, help prevent heat stroke by using a few ounces of water to wet the shirt down. (The water can come from anywhere, including that algae-edged stock tank.) The evaporation is what cools you!)
The same properties that make cotton a good choice for hot weather make it a killer in rain, snow and cold.
Typical urban casual garb is probably all cotton: sweat-socks, Hanes or Fruit of the Loom underwear, jeans, tee shirt, flannel shirt and sweatshirt. This outfit may keep you warm in town, but do not wear it into the back country! Once the cotton gets wet, you could end up in trouble.
Do not be mislead by the looks and camouflage patterns of 100 percent cotton hunting clothes. These garments my be just what you need for a hot, September dove hunt in Mississippi, but they become cold and clammy when damp or wet, just like anything else made of cotton.
* Polypropylene: This material does not absorb water, so it is a hydrophobic. This makes it a great base layer, since it wicks moisture away from your body. The bad news is that polypropylene melts, so a spark from the campfire may melt holes in your clothing.
* Wool: Where I live in Central Oregon, wool is the standard for six months of the year. A good pair of wool pants and wool socks are the first clothing items we recommend to new Boy Scouts in our troop. For our winter scout excursions, any sort of cotton clothing is strongly discouraged. Jeans are banned.
Wool absorbs moisture, but stays warmer than many other fabrics. Wool is also inherently flame retardant.
* Polyester: This is especially fabric made from plastic, and it's good stuff. The material has good insulation and wind-stopping value, and can be made into many different thicknesses.
* Nylon: The fabric is pretty tough and can be used on your outer layer. It does not absorb much moisture, and what does evaporates quickly. It is best used as some sort of windbreaker, to keep your clothing from being compromised by the wind.
* Down: This material is not a fabric, but rather, fluffy feathers stuffed inside a garment or sleeping bag. When dry, down is one of my favorite insulated materials.
But I do not use a down sleeping bag, and would hesitate wearing a down vest into the back country because of potential moisture problems. When wet, down becomes hydrophilic, and loses all its insulated value. It can be worse than cotton as far as sucking heat away from your body.
In addition, a down sleeping bag or garment is virtually impossible to dry out in the back country, even with a roaring campfire.