Will you be working outside this winter? You probably already know that the best protection is dressing in layers. But do you know how many layers to use or what materials work best to keep you warm?
Base Layer: The “keep-you-dry” layer. Starting at the skin, this layer should be soft (conforming but allow free movement), comfortable, thin and contain good “wicking properties.” Wicking is the ability of the material to pull the perspiration away from the skin toward the outer layers for escape. If moisture stays in contact with the skin, a “clammy” feeling results, and body heat is lost.
Insulating Layer: The “keep-you-warm” layer. This layer includes shirt and pants, and, depending upon weather conditions, you may need to add a vest as another insulating layer. The clothes chosen should be loose fitting and light-weight with good insulating properties (ability to trap air, but allow moisture to pass through).
Outer Shell Layer: The “protect you from the elements” layer. This layer should be wind-proof, water-proof, light weight and able to breathe. This layer does not need a lot of insulation unless temperatures will be below 0 degrees most of the time. Jackets should extend below the waist and have a hood. Look for elastic or drawstrings at cuffs and hems.
Later, when the day warms up, layering allows you to remove some clothes to prevent sweating. The different kinds of materials available are described below. Read clothing labels to choose the right material. Additional information can also be found at the President’s Council on Physical Fitness and Sports.
Cotton: While cotton is lightweight, breathable and comfortable, it has no “wicking” abilities. In fact, cotton absorbs, so it will stay wet and become heavy. In cold conditions, avoid cotton, including jeans, t-shirts, cotton socks and 100% cotton thermal underwear.
Down: Whether goose or duck down, it is still the best overall insulator. Down is lightweight, compressible and will last a lifetime. However, down can be expensive, and, when wet, it’s worthless, since it provides no insulation and takes a long time to dry. It is not recommended for sweat-producing activities. The “fill power” number on the label refers to how much down the material contains – the higher the number, the more down the garment contains and the more insulation it provides.
Fleece: This is a synthetic material with the same insulation properties as wool at half the weight. It is thin, soft, comfortable, easily laundered and will last years. It breathes well and dries quickly, so it can be worn for sweat-producing activities. Unfortunately, wind blows right through it making it unsuitable for the outer shell layer, but perfect for the insulating layer.
Nylon: Another synthetic material, nylon is usually woven tightly and coated with urethane to make it waterproof. It is best suited for the outer shell layer.
Polypropylene: This man-made material is thin, lightweight, conforming and soft. It provides the most “wicking,” making it the perfect base layer material.
Thinsulate: This was introduced as the synthetic replacement for down. It is very warm in surprisingly thin layers, resists becoming wet, but will maintain its warmth when soaked. Unfortunately, it lasts less than five years.
Wool: Wool has many great properties. Oiled and tightly woven, it is waterproof, an excellent insulator even when wet, has great “wicking” abilities and lasts forever. However, wool is heavy, takes a long time to dry and can be very itchy.
With the right materials and layers, you can make work (or play) outdoors in winter a safe, tolerable (and enjoyable) experience.