Unless you live in a warm climate year-round, it’s time to start reviewing the proper way to deal with the cold. There are four factors that contribute to cold stress: air temperature, wind, dampness of the air and contact with water and surfaces. When these factors are in place, injuries resulting in permanent tissue damage can be common. The Occupational Safety and Health Administration (OSHA), in its yearly Coldcard, illustrates this link with a simple reminder:
Low Temperature + Wind Speed + Wetness = Injuries + Illness
Three common conditions associated with cold stress are hypothermia, frostbite and chilblains. Normal body temperature is between 98.6°F and 99.9°F. Hypothermia occurs when the body temperature drops to about 95°F. This happens when the body loses heat faster than it can generate. OSHA classifies hypothermia as a medical emergency. Symptoms include loss of coordination; slurred speech; cool, bluish skin; confusion/disorientation; severe shivering; and possible death.
When hypothermia is suspected, emergency medical assistance should be called immediately. Until help arrives, the worker should be moved to a warm, dry area. Wet clothes should be removed and replaced with dry clothes or blankets. Be-cause muscles create a good source of natural body heat, someone with hypothermia should move their arms and legs. If the worker can’t move, place hot packs in the armpit, groin, neck and head areas.
Frostbite and its close relative frostnip are cold injuries related to the amount of heat circulating to the outermost body parts (fingers, toes, ears and the nose). The differences between frostbite and frostnip are the degree of freezing of the body part and the amount of damage caused. Frostnip occurs when the top layers of the skin are frozen and is generally reversible. It causes the skin to look very white and waxy, with the top layers feeling hard and the underneath tissue still feeling soft. The symptoms of frostbite are quite similar: The skin will appear white and waxy but will feel hard all the way through the skin. Frostbite can be reversible depending on the size of the area affected.
The most important thing to remember when helping someone with frostbite is never rub the skin that is affected. Ice forms within the skin cells when it freezes. By rubbing, the skin cells can be torn and destroyed by the ice.
The best way to warm the area is by placing it in a warm (105°F) water bath to slowly heat the tissue. The bath should last be-tween 25 and 40 minutes. Once rewarmed, the affected area should be lightly wrapped to keep it warm. If there is even a slight chance that the area may get cold again, it should not be warmed. If frostbitten skin is warmed and allowed to become cold again, extensive damage can occur, including tissue loss. A worker with frostnip or frostbite should seek medical attention as soon as possible.
Chilblains is caused by prolonged, continuous exposure to cold temperatures above freezing. This is most likely to occur when cold temperatures are combined with persistent dampness or actually being in water. Chilblains is often referred to as “trench foot” when it affects the feet. It is similar to frostnip and frostbite but is considered to be less severe. Symptoms of trench foot include swelling, tingling, itching and pain in the affected area with possible blistering and tissue death. The treatment for chil-blains is the same as treating frostbite.
The easiest way to prevent cold stress and its associated injuries is by planning. Planning includes protective clothing, safe work practices and training. OSHA recommends dressing in three layers when working in the cold. An outer layer (such as nylon or Gore-Tex) should be worn to block the wind and allow some ventilation. The middle layer should be down or wool, as these materials can absorb sweat and provide insulation even when wet. Cotton is not a good choice for this layer be-cause, once wet, cotton loses its insulation ability. The inner layer should be cotton or something that will allow ventilation, so sweat can evaporate. It also seems Mom was right: Always wear a hat. The body can lose up to 40 percent of its heat when the head is left uncovered. Wear waterproof and insulated boots and gloves to help keep the hands and feet protected.
Safe work practices also are important preventive measures. It is as easy to become dehydrated in cold as it is in hot weather. Workers need to drink plenty of liquids, avoiding alcohol and caffeine. Heavy work should be scheduled for the warmest part of the day, and frequent breaks should be allowed. Since it takes more energy to stay warm in cold weather, it is important to consume warm, high-calorie foods (such as pasta) to help maintain energy levels. Training to recognize early signs of cold stress also is very important and closely tied to safe work practices. Workers should be encouraged to take fre-quent breaks and watch for warning signs in each other. EC
KELLY is a safety and health specialist with Intec, a safety consulting, training and publishing firm that offers on-site assistance and produces manuals, training videos and software for contractors. She can be reached at 800.745.4818 or firstname.lastname@example.org. This article was edited by Joe O’Connor.