Dressing for Comfort

When we venture outdoors, we're subjected to the temperament of Mother Nature herself, for good or for worse. In certain places in certain seasons, the weather is pretty much predictable and choosing what to wear outside is an easy choice to make. However, things are not so black & white in certain other places where the weather can take a 180 degrees turn within minutes or where daily temperatures can differ up to a range of 20 degrees centigrade or more. Then there is a need to be sufficiently dressed for comfort. Dressing for comfort in the outdoors really means protecting yourself from the vagaries of wind, rain, and cold, plus the heat factor and the sun. What boils down is that our clothing are really our first line of defense against all that nature can throw at us.

The key to having an enjoyable time out there with Nature no matter how bad the weather conditions lies in the concept of layering a series of garment over the body to stay in tune with changing body temperatures and external weather conditions. In short, it means peeling off or adding available layers of clothing accordingly to suit the situation as temperatures or weather conditions change. Sounds simple but it takes experience, good judgment and lots of common sense to master this theory.

WAYS OF LOSING BODY HEAT

Our human body is designed for a tropical climate, and it ceases to function if its temperature falls more than a couple of degrees below 37 degree Celsius. To maintain our body's temperature at an equilibrium, it is useful to have an understanding how heat loss occurs. There are 4 ways by which our body loses heat :

Convective - occurs when the warm air adjacent to the body is replaced by fresh colder air. This is the major cause of heat loss. Convective heat loss is increased by wind, as measured by the windchill factor. It can be minimized by trapping the warm ( 'dead' ) air around the body by the provision of a windproof insulation.

Conductive - occurs when contact is made between your body and a cooler surface. Water is a good heat conductor and it can cool down the body rapidly. Conductive heat loss occurs 25 times faster with wet clothing than with dry ones. It can be minimized by not sitting on cold ground or wearing wet clothing.

Radiant - caused by the escape of infrared radiation from the body. It is minimized by wearing insulative fabrics or with reflective fabric that reflects the heat back to the body.

Evaporative - occurs when perspiration (water) on the skin evaporates, drawing heat from the body. Clothing must transport perspiration away quickly so that it doesn't use up body heat.

THE LAYERING SYSTEM

While the prime purpose of clothing is to keep us warm and dry in wind and rain, it also must keep us warm in camp when the temperature falls below freezing, and cool when the sun shines. The key to staying comfortable in any situation is using clothing layers that can vary according to what you're doing outside or what the weather is like. The layering system is one of the most important pieces of outdoor equipment, but it's not always understood. Comfort is not a magic button that can be pressed by purchasing sophisticated outerwear. But by applying a little knowledge of layering systems and common sense, it is possible to achieve comfort in a wide range of conditions. The modern weather protective layering system consists of 3 layers:

- A Base layer of thin, synthetic wicking material that removes moisture from the skin, - A thicker fleece Mid-layer to trap air and provide insulation, and - A waterproof/breathable Outer shell to keep out wind and rain while allowing perspiration to pass through..

THIS SECTION

• Ways of Losing Body Heat
• The Layering System
• Tips on Layering

The Wicking ( Base or Thermal ) Layer
The base layer should be worn closest to the skin. Its job is to wick moisture away from your body to keep the skin dry, thus minimizing wet conductive heat loss and ensuring your comfort. An effective wicking layer should be breathable and non-absorbent. Synthetic fibers like polyester and polypropylene are the best choices; natural fibers like cotton, wool, and silk are not, since they actually absorb and retain your body's moisture. They can become uncomfortable very quickly and then stay that way, since they dry very slowly. The base layer clothing can be found in a variety of fabric weights, from lightweight (for high activity sports where sweating is commonplace) through to mid weight (suitable as stand alone lightweight active shirts) and finally the thicker expedition weight garments (suitable for static activities or very cold conditions).

Thermal

The Insulating ( Mid ) Layer
The insulating layer's prime function is to trap air, an extremely effective insulating barrier. Worn over the wicking layer, the insulating layer is often made up of synthetic fibers, since they retain their insulating abilities even when wet. They also wick better and dry faster than natural fibers, such as wool, and tend to be less bulky, allowing greater freedom of movement. The insulating layer may consists of more than one garment, such as a thin lightweight fleece worn with a conventional mid-weight fleece. The best-known fleeces are Polartec® fleeces produced by Malden Mills and available under various brands.

Mid Layer

The Weather Protection ( Outer Shell ) Layer
You may know this layer as 'outerwear' or a 'shell.' It covers and protects all the other layers from wind, rain, snow and sun. If it's wet outdoors, this protective layer must be waterproof to ensure that moisture stays away from the layers beneath it, and it should also be windproof, to prevent convective heat loss with the trapping of warm air within. And finally, like all the layers in a clothing system, outerwear must be breathable, to allow your body's moisture vapor to pass through. Hence the better shell garments will come with ample ventilation options such as full-front zips, and underarms (armpit) vents.

All three layers are important ingredients in the comfort control formula. However, they don't all have to be worn at the same time. Vary them according to the weather and your level of activity.

WATERPROOF / BREATHABILITY
The moisture vapor given off by our body eventually reaches the outer layer of our clothing. If it cannot escape from there, it will condense on the inner surface of that layer and eventually soak back into our clothers. The solution is to wear fabrics that allow water vapor to pass through, while keeping rain out. These are known as waterproof / breathable fabrics. The best outer shell / raingear nowadays are made from breathable fabrics and the original and best well-known is GORE-TEX.

Water vapor can pass through a breathable fabric as long as the outside air is cooler than that inside. However, the quickest and most efficient way to let out moisture is by ventilating any garment by opening the front, lowering the hood, and unding wrist fastenings, or just zipping open the underarms vent pits.

TIPS ON LAYERING

Several thin layers of clothing offer better insulation and flexibility than one thick one because they trap air in between the layers as well as within the layers. It also offers the flexibility to fine-tune the amount of clothing you're wearing to match the current temperature. the ideal layering system seeks to combine elements of insulation, wicking, rapid-drying, breathability, durability, wind-resistance, and water-repellence in a lightweight combination which at the same time offers the necessary freedom of movement by the use of a few layers of garments. Of course, different people would adopt the system to varying degrees to suit their own particular situations.

FABRICS
Selecting the right type of clothing basically means choosing the type of fabrics the clothing is made of AND this decision can make THE difference between comfort or misery. For a detailed look at what type of fabrics are there in the outdoor wear market, take a look at the Clothing Fabrics Type page.

Outer Shell