Thursday, September 30, 2010


Although it is still warm in many parts of the country, now is the time to start thinking about and planning for the hazards of cold weather and the PPE needed to protect from them.

Outdoor workers are exposed to the hazards of cold weather. Prolonged exposure can result in serious health problems such as frostbite and hypothermia. The cold is also a leading cause of downtime and lost productivity

There is no exact temperature where the environment becomes hazardous. It does not have to be below freezing for frostbite or hypothermia to occur. A variety of factors, including wind, dampness and cold water, contribute to unbearable cold conditions.

Hypothermia occurs when the body looses heat faster than it is produced and body temperature drops below 95 degrees Fahrenheit. The first sign is pronounced shivering, followed by feeling tired and drowsy. Irritability and confusion can set-in along with a loss of coordination. If untreated, hypothermia may progress to slurred speech, irrational behavior, unconsciousness and ultimately heart failure. If any of these symptoms are observed, seek professional medical attention immediately. In the meantime, move the person to a warm dry area; remove any wet clothing; wrap in blankets; provide a warm, sweet-tasting beverage (no alcohol or caffeine); and gently move arms and legs to restimulate circulation.

A primary cause of hypothermia is wind chill. The combination of low temperature and wind velocity carries heat away from the body more quickly. For example, when the air temperature is 40 (F) degrees and the wind velocity is 35 mph, it is equivalent to a still air temperature of 11 (F). Wind chill is usually expressed in the form of an index. (For a wind chill index chart, visit the National weather service at

Frostbite is the freezing of deep skin tissue layers that leads to whitening, hardening and numbing of exposed skin. It usually affects the fingers, hands, toes, feet, ears and nose. If symptoms of frostbite are present, seek professional medical attention. Move the person to a warm dry area. Loosen or remove tight clothing that might restrict blood flow. Place the person in lukewarm (not warm or hot) water for 25 to 40 minutes to gradually warm affected tissue. Cover the area with dry, sterile gauze or bandages. Do not massage the area because it may cause greater injury.

There are also hidden cold symptoms such as disorientation, carelessness, slowed reaction time, reduced energy and difficulty concentrating that increase the risk of an accident. People who take certain types of medication and those with chronic illnesses such as diabetes, hypertension or cardiovascular disease face increased risk from the cold.

There is no specific standard for protection from cold working environments. OSHA recommends engineering controls and safe working practices and requires the provision of appropriate PPE whenever employees are exposed to hazardous cold working conditions.

Engineering controls begin with trying to shield the work area from windy conditions. The site should contain a source of heat such as air jets or radiant heaters and there should be a heated shelter where employees can take breaks to warm-up. Equipment handles should be covered with thermal insulating materials.

Safe work practices include allowing a period of adjustment by scheduling small interval exposure until workers become acclimated. Try to schedule work for the warmest time of the day if possible. Allow employees to set their own work pace to avoid fatigue or exhaustion. Never allow a worker to work alone so that someone can call for help if needed.

Personal Protective Equipment (PPE) for cold environments begins with layered clothing. The concept of layering came from skiing and mountain climbing clothing technology. But the Safety and Medical officials working on the Alaska pipeline more than two decades ago developed the practical application of the concept.

Cold weather layering is based on the use of three layers. The first (inner) layer should be cotton or synthetic weave to wick perspiration away from the body. The second (middle) layer should be wool or synthetic fabric to absorb sweat and retain as much body heat as possible. The third (outer) layer should be something like Gore-Tex or nylon to shield the wind and allow some ventilation. Workers do not have to wear all of the layers all of the time but they should have them handy in case the temperature fluctuates. The goal is to keep warm enough to be safe but cool enough so you do not perspire excessively.


Extended Winter Liner Sherpa lined
To protect from frostbite, as much exposed skin as possible must be covered. Good insulated gloves and boots, ear covers and facemasks are the PPE of choice for that purpose. Because about 40% of the bodies heat can be lost through the head, insulated hats are vital. When hard hats must be worn, quality winter liners should be worn under them. The liners should extend enough to cover the neck and the sides of the face.

Neck Warmer with heating channel
PPE technological advances in cold weather gear resulted in a new level of protection that combines protective clothing with a heat source for exposed workers. Heated winter liners, vests, head/ear bands, and neck warmers are now available from leading providers of PPE. The protective clothing contains heating "channels” or “pockets” that accommodate heat packs that produce warming of 130(F) degrees to 140(F) degrees for up to 8 hours and beyond.

Hot Hands Brand Heating Packet
The warming is produced by soft, lightweight packets that contain a mixture of non-chemical ingredients that, when exposed to the air, oxidizes to generate heat. The packets come in various sizes and can be used in standard clothing, gloves and boots in addition to the PPE specifically designed to use them. Having a personal source of heat allows workers to stay on the job longer and produce more. Heat packets can easily be stored in a toolbox, or glove compartment of a truck or car.

Workers must be trained to recognize hazardous cold conditions. They must be made aware and continually reminded of cold weather safe working conditions and the PPE needed to protect them. With the right training, good engineering controls, specific safe work practices and top quality, state-of-the-art PPE, out door, cold weather work sites can be safe and productive. For more in-depth information of the hazards of cold temperature extremes and the PPE to protect from it click on the link below.

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