Clothing for SAR - PART 2
This mini-lesson delves into the important aspect of using clothing for temperature control.
The Danger and the Killer
All year long, mountain weather can change from benign to life-threatening in a very short time. While most missions do not challenge the searcher's choice of apparel, it is imperative to carry proper clothing for the worst-case scenario.
As SAR personnel, we have two antithetical situations to handle. In one case, we are moving along the trail, creating warmth and perspiration. We need to avoid overheating and also release our perspiration to the air. The opposing situation is when we are stopped for an extended time (e.g., waiting for a litter or for a rendezvous with another team). Now our perspiration-wet clothing is no longer heated by our exertion, and the evaporation can rob our bodies of life-preserving warmth. Failure to account for this via proper attire makes us prime candidates for the killer of the mountain - hypothermia.
An in-depth description of hypothermia is beyond the scope of this lesson. Let's just define it as a condition where the body loses heat faster than it can be regenerated, possibly ending in death.
The Three-tiered Clothing System
This system is the proven solution to wilderness clothing problems. The standard definition depicts an inner layer which wicks moisture, a middle layer which provides insulation even when wet, and an outer breathable layer. The outer layer keeps wind and rain from penetrating to the insulating layer, while allowing water vapor from perspiration to escape. Representative fabrics for these layers are polypro, wool/fleece, and Gore-Tex, respectively.
Typically, clothing designed solely to repel rain is not breathable, so it does not allow perspiration to escape into the air. This can cause a situation where clothing under the rainwear is almost as wet as if it had been rained upon. One must keep this in mind when opting for standard rainwear over the three-tiered system.
In cold weather, avoid the temptation to add more socks while hiking, because they can cut off circulation required to keep your feet warm. A system that works well for most conditions is a thin liner sock covered by a heavier insulating sock. Extra socks should be reserved for replacing soaked ones. In addition, there are various outer sock coverings designed to keep hike-generated heat near your feet.
For boots in cold weather, choose the Sorel-type if you are going to be snowshoeing, in deep snow, or in severe cold weather, However, for most missions, leather hiking boots (properly treated for water-resistance) handle the job well, weigh less, and provide more support.
Shorts are not the best selection for SAR because they fail to provide protection from hazards. CSAR veterans opt for a pair of cotton/poly blend BDUs, which are quite comfortable in warm weather. If it's raining or you're going through wet flora, slip a breathable outer layer over the BDUs.
There are two situations in cold weather which are best handled by distinct legwear strategies.
When you are hiking, you'll generate a tremendous amount of heat and perspiration. Except in extreme cold weather, there is almost never a need to wear the three tiers of pants while moving. In fact, it is a prudent strategy to keep the insulating and windproofing bottoms inside your pack. For the minimum temperatures we generally encounter, polypro underwear covered by BDUs do the job quite well.
When you stop, add the wool/fleece insulating layer and the outer windproof layer early in the rest period, so you don't begin to shiver.
In general, the same concept about moving/stopping applies to torsowear. However, because the vital organs require it, you need to be more vigilant that the torso area is kept warm. Thus you'll want to don the insulating layers for your torso in conditions where your legs can be comfortable with less.
A large portion of body heat escapes through your head. A hat can therefore be used to regulate the temperature of your entire body. In warm weather, baseball-type caps with mesh sidepanels or the longer-brimmed outdoorsman equivalent are the apparel of choice. In cold weather, you should don/doff your winter hat (many varieties exist) as required to avoid perspiration but conserve desired heat.
Cotton and Down
During exertion in cold weather, 100% cotton garments get dangerously cold when wet. Many deaths have occurred because of hypothermia which cotton failed to prevent. The common portrait of the rugged outdoorsman in his cotton long-underwear undershirt, flannel lumberjack shirt, and cotton hooded sweatshirt is a picture of impending disaster.
Conversely, in hot weather, cotton is quite comfortable because it cools you as perspiration evaporates.
Garments containing down are excellent insulators per pound of material, but they lose most of their insulating value when wet. If you choose garments containing down, it's best to keep them safely dry in plastic inside your pack, and always prevent them from getting wet from perspiration or the elements.
Self-Quiz on Clothing - Part 2
- What medical condition can lead to death because of improper clothing?
- What are the layers of the three-tiered clothing system?
- Why is common rainwear not part of the standard three-tiered system?
- What is one problem with wearing extra socks in cold weather?
- Why should you wear a hat in the summertime?
- What is a drawback of using down for an insulating layer?
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