By Laurie Breyer, Brenda Jacklitsch /
It is that time of year again when the weather outside can get frightful. Not only does the drop in temperatures make outdoor work uncomfortable, but it can also be very dangerous. People who work in cold environments are at risk of cold stress. As winter weather starts to affect the nation, outdoor workers should be on the lookout for dangerous cold stress-related symptoms that could result in illness and injuries such as hypothermia, frostbite, trench foot, chilblains, dehydration, and sunburn. The National Institute for Occupational Safety and Health has created helpful outdoor work information to identify cold stress illness and injuries, their symptoms, and first aid steps to stay safe. NIOSH also has a list of general suggestions to help workers prepare for cold weather work.
Hypothermia occurs when the body loses heat faster than it can be produced. This leads to an abnormally low body temperature. Such a temperature drop causes the body to use up its stored energy, which prevents normal production of body heat. Hypothermia is dangerous because a body temperature that is too low affects the brain, making the victim unable to think clearly.
Symptoms of hypothermia can vary depending on how long the victim has been exposed to the cold.
- Loss of coordination
- Confusion and disorientation
- No shivering
- Blue skin
- Dilated pupils
- Irrational behavior
- Slowed pulse and breathing
- Loss of consciousness
Take the following steps to treat a worker with hypothermia:
- Alert the supervisor and request medical assistance.
- Move the person into a warm room or shelter.
- Remove any wet clothing.
- Warm the center of the person’s body (chest, neck, head, and groin) first, using an electric blanket if available or create skin-to-skin contact with the person under loose, dry layers of blankets, clothing, towels, or sheets.
- Warm beverages may help increase the body temperature, but do not give alcoholic beverages. Do not try to give beverages to an unconscious person.
- After the person’s body temperature has increased, keep him/her dry and wrapped in a warm blanket, including the head and neck.
- If the person has no pulse, begin cardiopulmonary resuscitation (CPR).
Frostbite is an injury that is caused by freezing body tissue. It typically affects the nose, ears, cheeks, chin, fingers, or toes. Frostbite can permanently damage body tissue and, in severe cases, can lead to amputation of the affected body part.
- Reduced blood flow to hands and feet (fingers or toes can freeze)
- Tingling or stinging
- Bluish or pale, waxy skin
Workers suffering from frostbite should:
- Get into a warm room as soon as possible.
- Not, unless absolutely necessary, walk on frostbitten feet or toes–this increases the damage.
- Immerse the affected area in warm–not hot–water (the temperature should be comfortable to the touch for unaffected parts of the body).
- Warm the affected area using body heat; for example, the heat of an armpit can be used to warm frostbitten fingers.
- Not rub or massage the frostbitten area; doing so may cause more damage.
- Not use a heating pad, heat lamp, or the heat of a stove, fireplace, or radiator for warming. Affected areas are numb and can be easily burned.
Trench foot is also known as “immersion foot.” It is caused by prolonged exposure of the feet to wet and cold conditions. Wet feet lose heat 25 times faster than dry feet. In fact, trench foot can occur at temperatures as high as 60°F if the feet are constantly wet. To prevent heat loss, the body constricts blood vessels to shut down circulation to the feet. Lack of oxygen and nutrients to the feet causes skin tissue to die. This condition also leads to a buildup of toxic products in the body.
- Reddening of the skin
- Leg cramps
- Tingling pain
- Blisters or ulcers
- Bleeding under the skin
- Gangrene (the foot may turn dark purple, blue, or gray)
Workers suffering from trench foot should:
- Remove shoes/boots and wet socks.
- Dry and warm their feet.
- In later stages, avoid walking on feet as this may cause tissue damage.
Chilblains are ulcers formed by damaged small blood vessels in the skin. They are caused by repeated exposure of the skin to temperatures just above freezing to 60°F. The cold exposure damages groups of small blood vessels called capillary beds. The damage is permanent and causes redness and itching that will return with additional exposure. Chilblains usually affect the cheeks, ears, fingers, and toes.
- Possible blistering
- Possible ulceration in severe cases
Workers suffering from chilblains should:
- Avoid scratching.
- Slowly warm the skin.
- Use corticosteroid creams to relieve itching and swelling.
- Keep blisters and ulcers clean and covered.
Dehydration and Sunburn:
Just because it is winter does not mean workers are safe from dehydration and sunburn. Be prepared with water or other liquids and sunscreen.
Being aware of specific types of cold stress is important, but there are also general outdoor worker tips to keep in mind. Of course, avoiding exposure to extremely cold temperatures is best. When that is not possible, try to schedule work during the warmest hours of the day. When that is not an option, follow these eight basic tips to keep yourself and your coworkers safe during this winter season.
1. Wear appropriate clothing.
o In most cases wearing several layers of loose clothing is better than fewer layers. Layering provides better insulation.
o Tight clothing reduces blood circulation. Warm blood needs to be circulated to the extremities.
o When choosing clothing, be aware that some clothing may restrict movement, causing a hazardous situation. In some situations where better dexterity is needed or where loose-fitting clothing could be dangerous (around machinery), it may be necessary to go with tighter clothes and fewer layers. Alternatively, workers could temporarily remove layers to complete the tasks and put layers back on to warm up. Make sure to protect the ears, face, hands and feet in extremely cold weather.
o Boots should be waterproof, insulated, and meet any other safety requirements. Consider layering socks, too.
o Wear a hat; it will keep your whole body warmer. (Hats reduce the amount of body heat that escapes from your head.)
2. Move into warm locations during work breaks; limit the amount of time outside on extremely cold days.
- Warm your body up and dry out clothes.
- Eat warm snacks and drink warm liquids.
3. Be careful when warming up. Temporary warming shelters can be dangerous. If heated incorrectly, they can cause carbon monoxide poisoning.
- Because it is colorless, odorless, and nonirritating, carbon monoxide can overcome people without causing symptoms. Do not allow the use of or operate gasoline-powered heaters inside buildings or in partially enclosed areas unless gasoline engines can be located outside away from air intakes. Use of gasoline-powered heaters indoors can cause fatal carbon monoxide accumulation.
4. Keep with you cold weather gear, such as extra socks, gloves, hats, jacket, blankets, a change of clothes, and a thermos of hot liquid.
5. Include a thermometer and chemical hot packs in your first aid kit.
6. Avoid touching cold metal surfaces with bare skin.
7. Monitor your physical condition and that of your coworkers. Work with a buddy. If this is not possible, a supervisor should routinely observe workers for cold stress symptoms.
More information on outdoor workers and cold stress can be found on the NIOSH website at: www.cdc.gov/niosh/topics/coldstress/.