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Safety Check: Cold Weather Safety Best Practices
Safety guru, Jary Winstead explains why what you donít know about winter clothing can lead to disaster in cold weather work environments. His suggestions can prepare your workers to face harsh weather conditions
By Jary Winstead
Date Posted: 12/1/2015
Frosty Weather Ahead
Safety guru, Jary Winstead explains why what you donít know about winter clothing can lead to disaster in cold weather work environments. His suggestions can prepare workers to face harsh weather conditions.
Last winter was one of the most brutal on record in the United States, and weather forecasts predict a similar situation over the next few months.
Pallet and lumber companies, which operate in tough winter environments, need to keep the weather in mind as it can contribute to an increased rate of injuries from slips, trips and falls. Also, winter weather can lead to higher incidents of vehicle accidents, electrical shock, frostbite and problems related to hypothermia.
According to the Bureau of Labor and Statistics (BLS), slip, trip and fall injuries, depending on occupation, makes up 18-30% of all job related injuries, and winter months are a great time for a safety committee to take a proactive walk around the workplace to identify and reduce these hazards.
In this article we will discuss how to protect workers from cold weather, how to recognize the symptoms of hypothermia and frostbite, and how to treat these serious conditions.
According to the Center of Disease Control (CDC), more than 13,400 hypothermia deaths occurred in the United States between 2003 and 2013 and the condition seems to be slightly on the rise as colder temperatures are recorded. The older we get, the higher at risk we are.
Heat Loss Basics
The human body loses heat in four ways through radiation, conduction, convection and evaporation. Radiation is the loss of heat to the environment due to the temperature gradient, occurring when the ambient temperature is below 98.6 degrees Fahrenheit. Factors important in radiant heat loss are the surface area and the temperature gradient. This is why insulating layers are so important.
Conduction occurs due to heat exchange through direct contact between objects, molecular transference of heat energy. This is why an insulated barrier between flesh and solid objects are important. Convection takes place as a process of conduction where one of the objects is in motion. Molecules against the surface are heated, move away, and are replaced by new molecules. The rate of convective heat loss depends on the density of the moving substance. Two types related to hypothermia are water and air. Water convection occurs more quickly than air convection. Yet, the faster air moves, as in wind chill, the more effect the moving air has on convection, and the faster body heat is loss. This explains why water proof and wind resistant outer shells are so important.
During evaporation, heat is transferred while your body is converting water from a liquid to a gas. This occurs in three ways; perspiration, sweating and respiration. This is why breathable clothing is so important. The more you exert yourself, the more important breathable clothing becomes.
Protective Clothing Basics
Being properly dressed for the cold weather conditions is crucial, and the correct way to dress is by layering. This does not mean a t-shirt, sweatshirt and your denim jacket. Cottons do not breathe well, and when wet, they will suck the heat right out of you, at reportedly a rate five times faster than normal.
Water conducts heat away from the body 25 times faster than air because it has a greater density, so staying dry means staying alive. When speaking of staying dry, this is more than just exposure to rain or snow. This also includes your body’s perspiration. For example, wools, polypropylene and fleeces of polyester make great garments for layering. Garments made of these materials still retain some insulating abilities even when wet. These clothing materials are also breathable, which allows moisture from perspiration to evaporate without the material becoming wet from perspiration. Even when wet, materials such as fleece will dry faster, than other materials.
Having layers allows you to shed clothing or to easily add clothing to adjust to the work load or temperature. A light weight base layer, an insulating mid layer, and a water proof, wind resistant, and breathable outer shell is a good example of proper layering. These days they even make heavy outdoor work coats made of waterproof and breathable materials. These garments used to be quite expensive, but now cold weather clothing has become much more affordable.
These performance factors does not mean that there is no place for non-breathable clothing, such as those made of cotton. For people who are not working in cold and wet environments, these clothing products are acceptable, and can be quite comfortable to wear.
It is also important to remember that a person can wear the finest winter clothing available, but without good footwear, gloves and a warm hat, a person won’t be able to retain body heat, and prevent frost bite.
With your head comprising about 10% of the body’s surface area, and 13-16% of the body’s blood volume, a hat is one of the most important pieces of clothing. A person can lose a dangerous amount of body heat when not wearing a hat, and exposed skin can become frost bitten very quickly during cold and windy conditions. Water proof, wind resistant, insulated, and breathable hats are your best protection during wet and cold days.
Wearing water proof, insulated and breathable gloves and footwear is another important part of your cold weather injury prevention. Handling and or standing on steel surfaces is one of the fastest ways to conduct heat away from the body. Steel conducts at a rate even faster than water. Insulated gloves and footwear will help prevent this type of heat loss, and unprotected hands can quickly become frost bitten.
There are three protective factors for clothing that you must remember – water proof, insulated and breathable. Having clothing with these three factors is the best protection you can have in cold and wet weather.
One common problem is that most fabrics with these insulating and moisture barrier properties are also flammable or are not safe when performing tasks such as cutting and welding. As a result, if your job entails hot work exposures, you need to select your cold weather clothing accordingly. Wool mid layers, and leather, canvas, or cotton shells treated with water resistant chemicals are much safer when performing hot work. Keep in mind, most of these materials are not breathable. Your work clothing supplier can help you with the best selection for your specific exposure.
Hypothermia Prevention Basics
Hypothermia begins when a person’s body temperature falls below 95 degrees. Hypothermia can occur with ambient temperatures above freezing or with water temperatures below 98.6 F or 37 C (normal body temperature). Since temperature drop may be gradual, the victim may not know a problem exists. Symptoms of hypothermia include: uncontrolled shivering or foot stamping, clumsy movements, loss of coordination, confused or irrational behavior, fatigue or drowsiness, slurred speech, a drop in blood pressure, shallow breathing, weak pulse, and a pinkish tint to the skin.
When observing someone having these symptoms, it is truly a life-threatening situation. A person experiencing hypothermia needs help immediately, call or have someone call 911. Get the person out of the elements and into a warm, dry place. If the individual has wet clothes on, take them off. Insulate all exposed body parts. Give them warm drinks, if they are conscious, but avoid drinks with caffeine, such as coffee, tea, sodas or hot chocolate, and never give alcohol. No, a shot of whiskey or brandy really doesn’t warm you up. In fact, it does just the opposite.
Most frostbitten body parts are white, yellow – white, or bluish white in color. They are hard and cold to touch. For treatment, remove wet or restrictive clothing. Wrap frost bitten parts with a warm dry cloth or sterile dressing. Protect the frozen parts from injury. Never rub frostbitten parts you will just cause more injury. Re-warming is best accomplished in a hospital or emergency department. Do not thaw frozen parts, if they have a chance of re-freezing.
Since many in the industry cannot stay inside when it’s cold, your best defense against cold related injuries is being properly prepared for the conditions. Do not allow yourself or your employees to work outside without being properly dressed for the weather. What you wear can mean the difference between going home in good condition or returning home at all at the end of the day.
Editor’s Note: Jary Winstead is a safety consultant, author and trainer who serves a variety of industries including the forest products sector. He owns Work Safety Services LLC and can be reached at SAFEJARY@aol.com.