Cold weather brings potential dangers Published Dec. 18, 2007 By 375th Medical Group SCOTT AIR FORCE BASE, Ill. -- Cold weather has arrived at Scott Air Force Base. As a result, everyone in Joint Total Force Scott must be aware of the threat of cold-related injuries. The unique climate here, including drastic day-to-day and even hour-to-hour temperature changes and wind conditions, can put people in unexpected danger. All personnel must be prepared at all times. Exposure to extreme cold can cause two major health problems: hypothermia and frostbite. When the body can no longer maintain its core temperature by constricting blood vessels, it shivers to increase heat production. Severe shivering develops when body temperatures fall to 95ºF. In addition, acute exertion in cold can constrict blood vessels in the heart. This is particularly dangerous for older people or those with coronary disease, who may have an increased risk of heart attack. Frostbite is a common injury caused by exposure to severe cold or by contact with extremely cold objects. It occurs more readily from touching cold metal objects than from exposure to cold air, because heat is rapidly transferred from skin to metal. The body parts most commonly affected by frostbite are the face, ears, fingers and toes. When tissue freezes, blood vessels are damaged. This reduces blood flow and may cause gangrene. Frostbite symptoms vary. They are not always painful, but often include sharp, prickling sensation. The first indication of frostbite may be skin that looks waxy and feels numb. Once tissues become hard, the case is a severe medical emergency. More severe frostbite results in blistering that usually takes about 10 days to subside. Tissue loss can be extensive; digits or more may be lost in severe cases. Damaged tissue will always be more susceptible to frostbite in the future. The best protection against cold-related health risks is to be aware and be prepared. Workers should be able to recognize the signs and symptoms of overexposure in themselves and others. Pain in the extremities may be the first warning sign and any worker shivering severely should immediately get out of the cold. The most critical aspect of hypothermia is the body's failure to maintain its deep core temperature. Lower body temperatures present the following signs and symptoms: * Persistent shivering -- usually starts when core temperature reaches 95ºF. * Irrational or confused behavior. * Reduced mental alertness. * Poor coordination. * Reduction in rational decision making. General information: * Educate workers who have potential prolonged exposure to cold on how to interpret and responde to wind-chill factors. * Ensure that workers are medically fit to work in excessive cold, especially those with cardiac risk factors. * Make sure that workers have access to high-caloric foods when working in cold environments. Warm, sweet drinks and soups should be arranged at the work site to maintain caloric intake and fluid volume. Coffee should be discouraged because it promotes water loss and blood flow to extremities. * Provide regular breaks under extremely cold working conditions. Proper clothing: * Wear several layers of clothing rather than one thick layer. Air captured between layers acts as an insulator. * Wear synthetic fabrics such as polypropylene next to the skin because these whisk away sweat. Clothing should not restrict flexibility. * If conditions are wet as well as cold, ensure that the outer clothing worn is waterproof or at least water-repellent. Wind-resistant fabrics may also be required under some conditions. * At air temperatures of 35.6ºF or less, workers whose clothing gets wet for any reason must be immediately given a change of clothing and treated for hypothermia. * Encourage the use of hats and hoods to prevent heat loss from the head and to protect ears. Balaclavas or other face covers may also be necessary under certain conditions. * Tight-fitting footwear restricts blood flow. Footwear should be large enough to allow wearing either one thick or two thin pairs of socks. Wearing too many socks can tighten fit and harm rather than help. * Workers who get hot while working should open their jackets but keep hats and gloves on. * Data obtained from electronic library of construction occupational safety and health