By Sean Curtis
It’s getting to be that time of the year when the temperature starts to drop, and while that may stop some outdoorsmen from doing their favorite activities, it doesn’t have to. In fact, if you’re properly prepared, you can hunt, hike, and camp all year long.
In my July column I mentioned how cotton kills when used in survival-type situations. Cotton is a great everyday fabric because it is light and breathes well, but this also means it’s very absorbent.
I also briefly wrote about Vietnam era camouflage and the worst and most frequent offender: blue jeans. But the topic of staying dry in cold weather needs to be addressed more thoroughly.
Clothing That Performs
There are a number of factors to consider when preparing for cold climates, not the least of which is performance capabilities of the materials you wear. What your layers do and what they are made of are also key factors to ensure you maintain good core temperature in even the most extreme conditions.
Imagine you are hunting in the mountains and the temperature is around freezing. You are not wearing layers, and trudging through the snow gets the bottom of your jeans wet. The water wicks up your pants and you feel it on your skin up to your knees. Consider this: heat loss is rapidly increased with the presence of water. It is not the same as full immersion in a body of water, but it is faster than normal conduction heat loss attributed to air.
One of the characteristics you want to look for in outdoor clothing is loft, which creates a dead air space that acts as an insulator, giving your body a barrier from the cold. When cotton gets wet, its loft collapses. Studies have indicated that wool retains up to 80 percent of its insulating abilities when wet. Keep in mind though, staying dry is key. Nothing insulates as well when it is wet.
The Insurance Policy: Your Base Layer
Each layer you choose needs to serve a distinct purpose. For example, your base layer needs to give you insulation, but also wick moisture away from your body. My recommendation is wool — preferably Merino wool. It has amazing insulating capabilities, wears well, and is resistant to odors. You will pay a premium for a base layer made of Merino wool, but think of it as an insurance policy.
Some think of wool as scratchy or uncomfortable. With Merino wool, this couldn’t be further from the truth. The finer fibers are much smoother than standard wool, but have the same insulating properties.
Recommended base layers:
A Balancing Mid-Layer
The next layer in the strata is the mid. This layer does not need to be water resistant like your outer shell, and does not need to wick moisture away like the base, but it needs to be warm. Loft may be a consideration depending upon how adverse your weather is. Flannel, fleece, and wool are all examples of this.
Keep in mind that managing your temperature means managing your moisture level. This seems counterintuitive, but even on the coldest days, exercise and a good jacket can lead to perspiration. Too much of this is a bad thing; if you start to sweat, you need to make an intelligent decision about reaching that ideal temperature. You can unzip your jacket to varying degrees, or take it off provided you aren’t going to get soaked from rain or snow. Finding the balance to stay dry from the inside-out is key here. The mid layer should be capable of handling this balance.
Recommended mid layers:
PhD® SmartLoft Divide Full Zip Jacket – For Men – For Women
Tru-Spec Polypropylene - GEN-III zipper neck thermal tops
The Outer Shell
The final layer is critical. The outer shell is your initial line of defense against the elements. All of the layering you do is for nothing if you cannot keep that moisture out in the first place. Again, performance fabrics are critical. Gore-Tex, some weights of nylon, and treated fabrics can offer different degrees of protection from moisture getting in. You also want this fabric to be able to breathe, letting out moisture with minimal loss of heat. Loft is also a critical factor to consider. If your mid layer does not provide loft, make sure your shell does.
Consider venting options also. Some jackets have specific zippers built in, such as in the armpits, to allow controlled heat loss. Build your clothing to accommodate your worst-case scenario. Using layers allows you the flexibility to dress down when it’s warm, and pile on when it’s cold. Read your product descriptions carefully and look for “water proof,” not “water resistant.” Consider the 5.11 Aggressor Parka for an all-in-one system. It has a waterproof shell, a fleece zip-in jacket for insulation, a hood, and several utilitarian features built for various emergency services.
Recommended Outer Shell:
Build a system that has three layers and give careful consideration to the mission of each layer, and what material best suits that mission. Sleeping bags have ratings of what kind of insulation they offer and it is rated in degrees of Fahrenheit. Try to think about how you would rate a clothing system and what kind of weather you might be in. If your lows at night are only in the 30s then plan for zero degree weather as a safety buffer and dress accordingly. If the weather looks like it will be around zero, plan for -20 and you’ll be glad you did.