Wearing for the Weather

There is an old adage that goes something like, "there is no bad weather, just bad clothing." Being properly dressed for the weather can make or break an outdoor experience. This section will cover the basics of clothing and how to dress appropriately for the conditions.

*The following information relies heavily on personal experience and the National Association for Search and Rescue's (NASAR) Fundamentals of Search and Rescue 2nd Edition handbook.*

Winter Hike

Clothing Materials

Clothing is made up of small fibers and has unique characteristics depending on the type. There are natural fibers and synthetic (man-made) fibers. Modern outdoor clothing has advanced dramatically over the years and some of the best producers of outdoor clothing have scientifically produced garments that use fibers in various proportions to work effectively in specific environments. Fibers may be hollow, oily, chambered, scaled, porous, long, short, thick, curly, straight, hydrophobic (water repellant), hydrophilic (absorb water), or any combination of these. What follows is not an all-inclusive list of available fibers, as many combinations and variations exist. It is up to you to do your best to research what clothing material will best suit your needs.

Cotton is the most common natural fiber and is hydrophilic. As it absorbed moisture, it may lose up to 90% of its insulative properties. This makes it great in hot conditions, but a poor choice when worn inappropriately during cold weather (this gives rise to the SAR saying, "cotton kills"). Canvas is a tightly woven cotton textile that has increased strength, durability, and abrasion resistance. Additional properties of cotton are:

  • It Burns easily but does not melt.

  • Can be heavy, especially when wet.

  • Light-colored, thin cotton is excellent for hot, dry climates because of its breathability and high ability to absorb water.

  • Generally abrades easily unless blended with tougher synthetics or woven tightly and heavily.

  • It rots under continued wet or hot and sunny conditions.

  • Thick cotton dries slowly from the outside, which is beneficial in hot, dry weather and detrimental in cold weather.

  • Tightly woven cotton makes a good windbreak and may be water-resistant, but it can also be heavy.

  • It can freeze solid when wet in extreme cold.

  • When cut or torn into strips, it can be used as a bandage, cravat, sling, or fire starter, and has multiple other uses.

True wool is spun from the fleece of sheep, but other fibers--also referred to as wool but from alpacas and lamas (camelids), and goats (cashmere)--have similar characteristics and are often softer and more expensive. Merino wool comes from Merino sheep and is coveted for its softer feel. The main advantage of wool over other fibers is that it maintains its insulative properties even when it becomes wet. Wool has naturally curly fibers which trap air in tiny pockets. Natural wool also contains the compound lanolin, a wax secreted by glands of wool-bearing animals, which repels water. To keep wool water-resistant, it is recommended to launder wool clothing less frequently so that these hydrophobic properties do not diminish as quickly. Some individuals may be sensitive to wool, but the fiber remains one of the best insulating natural fibers available. Additional properties of wool are:

  • In extreme coldiIt generally does not freeze solid when wet.

  • It burns very slowly and is very resilient, breathable, and durable.

  • Tears easily in its pure form, so is often blended with stronger materials.

  • May exude an unpleasant odor when wet.

Silk is a natural hollow fiber and fabric made from it is valued in cold weather. It is one of the lightest, strongest, and softest of all natural fibers. Its hollow structure wicks moisture away from the body and makes it a good insulator. It can be more expensive than other natural fibers and is often blended with other materials to reduce the cost. Additional properties of silk are:

  • It is very comfortable against the skin, traps air, and is very light.

  • It is relatively expensive and tends to hold odors and stains.

  • Silk is damaged by hot iron, inorganic acids, sunlight, perspiration, strong soaps, and alkaline substances.

Down is a soft type of feather found beneath the larger, tougher feathers of a goose or duck. It is an excellent insulator when dry because it is able to capture large pockets of air between its plumes. Down is also very lightweight and compressible. As an insulator in cold, dry conditions, it is superior to almost every other substance; however, when it becomes wet it is virtually useless. Down garments should be stored in an uncompressed state to prevent the plumes from being damaged and settling, and some down clothing requires periodic maintenance. Additional properties of down include:

  • It clumps with moisture and dampness.

  • It absorbs and retains odors and will mildew when damp.

  • Some people are allergic to down, but in many cases, the associated allergies are from dust mites and mold from inappropriately handled clothing.

Polyester is the generic term for any petroleum-based fiber. Loosely woven polyester is a great insulator but does not stop the wind, whereas tightly woven polyester is great at stoping wind but a poor insulator. The two types of weaves can be combined to obtain the best of both worlds. Time, repeated use, prolonged compression, and multiple washings will cause polyester fibers to break down, which can lead to a loss of their insulative, moisture-wicking, or wind-blocking properties. 

 

Polypropylene is durable, dries rapidly, insulates when wet, and wicks moisture well. It has one of the highest insulates of any synthetic fibers; however, it stains easily, melts at relatively low temperatures, and retains odors. This is why it is typically replaced with new synthetic materials like Capilene, Coolmax, and Polartec.

Nylon is another polymer fiber, which is stronger than cotton, abrasion-resistant, quick-drying, almost completely impervious to water and water-repelling compounds when woven together. This makes it a poor choice for clothing close to the skin because body moisture will remain trapped. A type of high-quality nylon, known as "RipStop" is threaded in such a way that if a tear occurs, it should stop at the next cross-thread. Cordura is another variety of nylon that is designed to be abrasion-resistant, lightweight, and comes in a range of deniers (stitches per unit area). It can be woven into ropes and is commonly used to make windproof membranes. Additional characteristics of nylon include:

  • Retains high strength when wet.

  • Resists alkali, mildew, and insect damage well.

  • Resists abrasion.

  • Washes and dries easily.

  • Blends well with other fibers.

  • Does not absorb much moisture.

  • Can be damaged by sunlight.

  • Has a melting point of 505 degrees Fahrenheit (263 degrees Celsius), but may be malformed well below that temperature).

  • Absorbs and holds perspiration and body oils.

  • Can be easily damaged from sparks and embers.

Waterproof versus Water Resistant

Waterproof material is impermeable to water, even water under pressure. Water-repellent sheds water that is not under pressure; however, intense rain or falling water may penetrate the fabric. Water-resistant material temporarily resists water under pressure. Some materials, such as Gore-Tex are laminated and can be waterproof and breathable at the same time. Material that resists wetness can be complex and confusing, but the videos below do a great job explaining how things work:

Layering

As we move around our bodies generate heat. In hot conditions, this heat can build up to unsafe levels. In cold conditions, the external temperature can dissipate the heat faster than we can generate it. By utilizing multiple thin layers of the appropriate type of clothing, we can control how fast our body's heat escapes into the surrounding atmosphere. This helps us maintain a healthy core temperature regardless of what weather conditions we are experiencing. The ideal layering system seeks to establish a balance between breathability, movement of moisture away from the skin (wicking), quick-drying, insulation, durability, wind resistance, and water repellence, all while remaining lightweight and offering freedom of movement with a minimum amount of bulk. Sounds like a tall order, but with a little experimentation, the right balance can be achieved. The three recommended layers are a wicking layer, an insulation layer, and a protective layer. NASAR recommends following the "BUBU" criteria for SAR operations.

  • Big: clothing should be able to fit an additional layer underneath.

  • Uncontstricting: clothing should not be tight, especially around the wrists and ankles.

  • Baggy: clothing should be loose enough to allow freedom of movement.

  • Ugly: clothing should be highly visible and focus more on function rather than fashion.

The wicking layer is intended to be worn against the skin to help regulate body temperature by moving moisture, including perspiration, away from the skin. This layer should be snug enough to avoid wrinkles that cause irritation, especially from belts, harnesses, pack straps, or outer layers. But not too snug to restrict movement or blood flow. Some people choose to wear cotton undergarments for discretion or hygiene, but in cold environments, this material will not provide proper insulation. In hot environments, moisture held by cotton undergarments can cause chaffing or irritation over time. These days there are better synthetic or natural-synthetic composite options that should be considered. The wicking layer is important because moisture close to the skin can potentially lead to hypothermia or hyperthermia.

 

Socks are also an important factor of the wicking layer because inappropriate use of socks can result in fabric clumping up against the feet, or cause constriction or abrasion. Cotton socks are not recommended for SAR operations, especially in cold weather. The recommended way to wear socks for walking long distances or strenuous activities is to utilize two layers: one thin, smooth, wicking layer against the skin, and on wool or wool blend insulating layer for insulation and cushion.

This video further explains the function and importance of having a good wicking layer:

The insulating layer includes any clothing worn over the wicking layer. Using multiple, thinner style insulating layers is often a better choice than choosing one thicker, bulkier layer. Openings such as vents and zippers are also important to consider, especially in places where heat builds up faster, such as near the armpits or back (when a pack is worn). Another important consideration is to find insulating layers that are able to retain their heat even when wet.

The protective outer layer protects the wearer from dirt, wind, sun, sand, rain, and snow. It should be capable of covering the head, neck, torso, legs, and arms. It should also be able to fit easily and loosely over any insulation layers without compressing them. A protective layer with multiple pockets is a useful feature for SAR operations.

There are too many variations of these layers to reasonably go over each one, and the best idea is to start with a simple three-layer system and adjust it as you need to. Its also important to test out your layering system in the environment you intend to wear it in, before spending any extended time in the outdoors. The video below will summarize everything in this section:

Additional Clothing Considerations

Clothing color, especially on outer layers, have an impact on several aspects of SAR operations. Dark colors absorb heat and are generally better in cold climates. At the same time, dark colors are difficult to see at night and in wooded environments. Lighter colors reflect heat and are better suited for warm conditions. Light colors are also easier to see in dark or wooded conditions. Besides heat regulation and the myriad of visibility conditions, SAR personnel should wear colors that are easily seen. Wearing a high visibility vest or fluorescent colors are good options to stand out and be easily identified. Camouflage colors should be avoided in SAR operations.

An unprotected head can be lead to a loss of more than half the body's heat loss in a cold environment, and a similar amount of heat gain in a hot environment. Utilizing a head covering is important in cold weather because the head has relatively little insulation of its own. In hot weather, a brimmed hat can protect the neck, ears, and face from radiant heat from the sun and prevent sunburn. The same layering considerations applied to clothing the body should be taken for the head.

Necks perspire and radiate heat. That means if conditions are cold and windy, they can become a source of excessive heat loss. Normally, scarves are the garment of choice, but in SAR operations, something like a neck gaiter or balaclava can produce the same insulating and moisture-wicking effects without the bulkiness of a scarf.

Fingers and hands are affected by extreme heat and cold, and as such, need special attention to prevent potential environmental injuries. In cold weather, mittens keep the fingers warmer but limit dexterity. Fingered gloves improve dexterity but can potentially lead to cold weather injuries. Overmits or glove liners can be worn over lighter fingered gloves as a solution, but again their use depends on conditions. Leather gloves may be necessary for SAR operations, but should not be used exclusively as they do not insulate or protect from moisture well. Fingerless gloves are an option, but they are not ideal for cold conditions.

Taking care of your feet is one of the most important things you can do while conducting SAR operations. Besides using proper socks, comfort, stability, support, durability, traction, and protection from the elements, are important footwear factors. When wearing boots or hiking shoes, there should be plenty y of room for the toes without the foot slipping forward or back during uphill or downhill travel. There should be no heel rise when walking, and there should be no pressure points. Because of all the subtleties of properly fitting footwear, it is strongly recommended to be fitted by a professional. Your choice of footwear is going to depend heavily on the terrain and climatic conditions of the region you will be working in. Once purchased, footwear should be broken in before heading to the field. You can break in footwear by simply wearing them around the house for a while to test their fit. Watch the video below to learn some simple tips to help break in your footwear:

 

 

 

 

 

 

 

 

 

 

 

If a problem arises, most manufacturers have an exchange policy.NASAR has several useful tips for taking care of your feet while conducting SAR operations:

  • Examine feet at the end of every day and clean them thoroughly.

  • Tend to any hot spots immediately. A "hot spot" is a reddened, slightly tender area on the skin of the foot that is evidence of rubbing or pressure from footwear and is an early sign of a developing blister.

  • Always wear clean, dry socks.

  • Consider wearing two pairs of socks for fieldwork.

  • Avoid folds in socks while they are being worn, and prevent seams from causing pressure on feet.

  • Air dry feet often, but do not soak or rinse them until the end of the day.

  • Keep toenails trimmed, but not too short.

  • Tighten footgear on inclines and loosen them a bit on flat ground.

  • Have footgear properly sized by a professional.

  • Keep your feet dry.

NASAR Clothing Survival Tips

  • When your feet are cold, put on a hat.

  • Do not overheat so that clothing becomes wet by perspiration. If clothing becomes wet from perspiration, remove and/or replace the wet layer and slow your pace.

  • Use the layering system; add layers when cold and remove layers when hot.

  • When sleeping in harsh, cold conditions, arrange dry, spare clothing around the neck and shoulders with padding and insulation added to each kidney region as these areas are more susceptible to cold. Also, wear a knit stocking cap because if your head is warm, chances are your feet will be too.

  • Dry wet clothing by allowing it to freeze and then beating the ice crystals from the fabric.

  • Wearing darker clothing in winter to absorb the sun's energy may be a good idea, but beware of not being visible enough. SAR personnel must be highly visible.

  • Clean clothing allows proper ventilation through clothing layers. Dirty clothing inhibits ventilation and causes moisture buildup on clothing layers. Wear clean clothes.

  • Light-colored clothing reflects the sun and heat in warm weather.

  • In hot weather, wear clothing that promotes the circulation of air beneath garments.