Thursday, January 19, 2012

The Warm Winter Wardrobe

For a variety of reasons, people spend time outdoors in the winter. Exercising, shoveling snow off sidewalks, or just getting to work or the grocery all expose our relatively poorly insulated bodies to the cold. This is where wearing the right clothing can make the difference between being protected and comfortable or vulnerable and miserable. The following common sayings related to dressing for the cold may not be completely accurate, but all contain a valuable message.

"If your feet get cold, put on a hat"

The notion that the body loses more heat from the head and neck has been somewhat dispelled. Studies have shown that the rate of heat loss is essentially the same for any exposed area of the body. Since the area of the head makes up approximately 10 percent of body surface area, heat loss through the head while at rest accounts for only 7-10 percent of total heat dissipation. The amount of heat loss from the head, however, does increase temporarily when initiating exercise due to increased blood flow to the brain. In someone shivering with hypothermia, the percentage of heat loss through the head and neck can increase dramatically reaching as high as 50%. From this, it could be assumed that as someone is becoming progressively colder, more and more heat loss is occurring from the head and neck. Therefore, covering the head and neck makes sense in order to prevent heat loss. Usually this means wearing a hat and scarf. Wearing a hood or balaclava (facemask) also helps to prevent heat loss. Conversely, should you begin to overheat, take off your hat or scarf to vent quickly.

"Cotton kills"

While the saying is somewhat of an exaggeration, cotton clothing ranks at the bottom of the list of appropriate fabrics for cold weather use. With outdoor activity, perspiration is absorbed into any cotton clothing touching or near the skin. As the air pockets in the fabric fill up with water, it ceases to provide insulation. A damp layer of clothing against the skin pulls heat away from the body and can rapidly lower body temperature. Furthermore, when it becomes wet, cotton clothing takes much longer to dry than comparably weighted synthetic fabrics. Garments labeled as corduroy, denim, flannel, or duck are mostly, or entirely, made from cotton. Clothing made from synthetic fabrics or wool are more appropriate and functional for winter wear.

"Dress in layers"

Instead of wearing a single heavy garment, there are several advantages to dressing in layers. This is particularly true during physical activity. The basic idea is that warm air is "trapped" between the layers providing more warmth to the body. Other advantages include wearing special layers designed to keep the skin dry, to provide insulation, and to protect us from wind and rain. Synthetic fabrics, such as Capilene, and Coolmax work best as base layers, worn against the skin. These fabrics keep the skin dry by "wicking" moisture away. A middle, insulating layer of wool, synthetic fleece, or Thinsulate works by trapping air to keep you warm. Goose down is also a great insulator, but it loses almost all of its insulating properties should it become wet. The outer shell layer should be both windproof and waterproof. Ideally, this garment also "breathes" to allow moisture to escape from the body. Gore-Tex and Entrant are trade names of fabrics with these characteristics. Using layers of clothing also allows you to control your temperature more effectively. Should you become overheated or begin to sweat during activity or exercise, you can remove or open up a layer to ventilate. As you cool down, zip up or add a layer.

"Mittens are warmer than gloves"

To a large degree, the warmth of mittens or gloves depends on the insulating properties and thickness of the materials used in their construction. All things being equal, however, mittens are warmer than gloves because the extra air inside creates added insulation, and because fingers maintain their warmth better when they are touching. "Dressing in layers" can apply to the hands also. For example, a thin glove liner beneath a mid-weight glove or mitten can be warmer than a single heavy glove. Be sure that your gloves are not too tight – constricting circulation can lead to cold hands. If exerting yourself in cold, wet conditions, consider carrying a spare pair of gloves or mittens in the inside pocket of your jacket. This gives you a warm, dry set of hand wear to put on should your fingers become cold.

An old Norwegian saying sums it up: "there is no such thing as bad weather, just bad clothing". Wintertime can be a wonderful time to get outside, but not if your clothing is not up to the task. A little preparation and the right combination of clothing can make all the difference in your winter outdoor enjoyment.

No comments:

Post a Comment