Improve Safety by Dressing for the Weather

Wearing the right apparel in hot, wet, or cold conditions can help a worker stay productive and safe.

• By Paul Aiken
• Aug 01, 2004

WHAT matters is not how much you wear, but what you wear to stay dry and comfortable while working in hot, wet, or cold conditions. When a workers' body overheats or drastically cools, it makes him or her lose concentration and greatly affects his performance. Wearing the right apparel helps with productivity and safety.

Dressing for the occasion is especially important in environments where workers are exposed to harsh weather conditions for long durations.

Layering is the key to staying dry, warm, and safe in adverse conditions. Typically, a three-layer system of dress provides a comfortable level of warmth for workers who spend hours at a time outside in colder conditions.

The first layer, called the base layer, is close fitting and moves perspiration away from the skin, keeping it dry and warm. The second layer, or thermal layer, is designed to insulate the body from cold conditions. It assists the base layer in moving excess moisture away from the body. The outer protection layer provides a shield that keeps rain, wind, and cold from getting too close to the body. For warm and wet conditions, a loose-fitting synthetic-fabric layer next to the skin and a lightweight protective shell are enough to provide a dry, comfortable, and safe work environment.

Base Layer: Cotton T-shirts are a popular alternative when it's warm, but they're the wrong things to wear next to the skin in wet conditions. It is vital to stay dry and regulate body temperature through venting or shedding layers when conditions improve.

Wool is a better natural alternative that maintains its warmth properties even when wet. Synthetic base layers made out of fibers such as LIFA technology--a polypropylene fabric--work best to quickly move excess moisture away from the skin and maintain a comfortable level of body heat.

Loose-fitting shirts made with fast-drying synthetic fabrics are an appropriate single layer in warm to hot conditions.

Thermal Layer: The middle apparel layer provides the greatest amount of warmth in the three-layer system. Fleece jackets, crews, and pants are popular thermal layer garments and are recommended for their insulating properties.

Warm air gets trapped in the loft of the pile while moisture can still move to the outer layer, where it turns into water vapor. Wool is the best performing natural thermal fiber that maintains its warmth properties while holding on to moisture longer than the synthetic alternatives.

Outer Layer: Outerwear comes in a variety of fabrics and styles designed for specific work environments, including high-visibility, flame-retardant, and fully waterproof jackets, pants, and bibs. PVC, IMPERTECH® (Polyurethane), and waterproof/breathable fabrics are popular materials used for rain, snow, and wind protection.

Polyvinyl-chloride (PVC) multi-coated fabrics are absolutely waterproof, durable, and a good value for long-term use. The coatings resist chemicals, oil, grease, saltwater, and sunlight, and they are machine washable.

IMPERTECH® (Polyurethane) jackets and pants are a lightweight alternative to PVC. A waterproof PU coating on a soft knit backing material results in a unique stretch fabric that is highly durable and comfortable.

Waterproof-breathable garments are popular in outdoor work environments. The fabrics are durable, lightweight, and allow excessive body heat to escape. They still provide a shield against rain, snow, and wind.

Dry equals warm when it comes to dressing for weather. Apparel worn on the job should work with the body to move sweat and excessive heat away from the skin and still insulate and protect the worker from the elements. Investing in the right base, thermal, and outerwear garments will ensure workers can remain comfortable and safe on the job over a longer period of time.

This article originally appeared in the August 2004 issue of Occupational Health & Safety.