I know it is not cold here in North America yet, but during the winter months in North America winter hazards abound. Now is the time to learn how to control or eliminate those hazards. People usually work during these periods keeping the roads open, fixing frozen and broken pipes, and completing a variety of other tasks. This exposure puts them at risk of cold weather injuries. Individuals must know the warning signs of cold weather injuries and heed them. The best way to prevent or reduce the occurrence of cold weather injuries is to know what cold weather injuries are, how they occur, how serious they are, first-aid treatment, and what can be done to prevent them. This blog post will highlight just that information and help people prepare for cold weather.
Before discussing the prevention of cold weather injuries, it is important to understand the concept of wind chill. This is important because the human body is continually producing and losing heat. When the wind blows across the body, it removes heat making the body susceptible to cold weather injuries. The combined effect of wind and temperature is expressed as an equivalent temperature, see figure 1 next page. Locate the ambient temperature across the top of the figure and run a finger down to the wind speed that is the temperature that the body is feeling. For example, if it is 15° Fahrenheit (F) and the wind is blowing 30 miles per hour the body is experiencing a temperature of -5° F, which is much more dangerous to the body than 15° F.
Cold weather injuries come in various shapes and sizes, so to speak. Hypothermia, Frostbite, and Trench Foot are the most common. There are often extenuating factors that increase ones’ risk of experiencing a cold weather injury or perhaps making an injury worse, these include:
- Acclimation to cold weather
- Length of exposure
- Previous cold injuries
- Use of prescriptions drugs
- Consumption of alcoholic beverages
The next few paragraphs will highlight the different types of cold weather injuries and provide useful information for prevention. It is important to remember that it is always easier to prevent a cold weather injury than to treat one after it occurs.
Hypothermia is a lowering of the body temperature caused by exposure to the cold. It is aggravated by moisture and the wind. Hypothermia occurs when the body is unable to produce heat as quickly as it is being lost. Most hypothermia cases develop in air temperatures between 30 and 50° F. It is important to note that a person will die if the internal body temperature drops below 78.6° F, making this a deadly injury. The moment one begins to lose heat faster than the body can replace it, they experience exposure. This is followed by the body taking drastic measures to conserve its energy and maintain the temperature of internal organs. As the body’s core temperature drops the symptoms develop.
The treatment of hypothermia consists of stopping or at least reducing the heat loss from the victim’s body. This is followed by adding heat to the victim’s body. This is best done by:
- Getting the victim to a sheltered area even if it is a warm vehicle.
- If the victim is wet, replacing the victim’s wet clothes with dry ones.
- Giving the victim warm, non-alcoholic drinks.
- Getting the victim to a hospital or medical clinic as soon as possible.
The prevention of hypothermia consists of:
- Dressing properly in layers (wear a hat and gloves or mittens).
- In the rain, choosing rain gear that works against wind-driven rain.
- Using the buddy system or working in pairs so help is nearby if needed.
- Knowing the weather and taking precautions based on the forecast.
Frostbite is the freezing of the skin and tissue of a body part exposed to temperatures of 32° F or below. The first symptom is an uncomfortable aching sensation, tingling, or stinging. If the condition is allowed to continue, numbness sets in. The skin initially turns red, later becoming pale gray or waxy white. In extreme cases, Frostbite can be very serious and result in the loss of or permanent damage to a body part. People have lost fingers and toes from Frostbite.
Frostbite occurs superficially and deep. Treatment depends on the degree of frostbite injury. The longer a body part has been without feeling, the more severe the frostbite. If the time is very short, the frostbite is probably superficial. Otherwise, you should assume the injury is deep and therefore, serious. In the case of deep frostbite seek emergency medical treatment immediately. While waiting for emergency medical care, protect the frozen part of the body from further injury by heeding these do’s and don’ts:
- Do keep the parts of the body not frozen warm.
- Don’t thaw frozen body parts by rubbing, bending, or massaging.
- Don’t soak the frozen area in either cold or warm water.
- Don’t rub the frozen body part with snow.
- Don’t expose the frozen body part to hot air, engine exhaust, or open fires.
- Don’t use ointments or salves.
The prevention of Frostbite consists of:
- Dressing properly in layers to keep the body warm.
- Always wearing a hat and gloves or mittens.
- Avoid wearing clothing that interferes with circulation. Tight-fitting shoes, socks, and gloves are especially dangerous.
- In rain choosing rain gear that works against wind-driven rain.
- Using the buddy system or working in pairs so there is help nearby if needed.
- Knowing the weather and taking precautions based on the forecast.
- Exercising your face, fingers, and toes to keep them warm.
Trench foot is caused by prolonged standing in water or by having wet feet for hours while exposed to a temperature just above freezing. The stages of trench foot are:
- Early stages-feet and toes are pale, numb, and stiff while walking becomes difficult.
- Later stages-feet and toes become red, swollen, and warm, which can include flesh dying.
There are several reasons the feet are susceptible to Trench Foot that include:
- The feet are far from the heart causing the heart to pump blood longer distance to warm feet.
- When standing for long periods, blood circulation can slow.
- It is easy for the feet, even in waterproof boots, to get wet.
- Tight socks or tight-fitting boots can restrict circulation.
The best prevention for Trench Foot is a good pair of shoes or boots and socks that fit properly. Here are a few dos and don’ts:
- Do dry, wet feet as soon as possible and put on dry socks.
- Do dry the inside of boots and shoes.
- Do seek medical attention as soon as foot problems occur.
- Do exercise the feet by stamping, stepping back and forth while flexing and wiggling the toes when working out in the cold.
- Do handle feet gently.
- Do wash feet carefully using mild soap and water.
- Do dry and elevate the feet leaving them uncovered and at room temperature.
- Don’t rub or massage them.
- Don’t restrict blood circulation by wearing tight socks or lacing shoes too tightly.
With people out and working in the hazardous winter weather it is important to know what cold weather injuries are, how they occur, how serious they are, first-aid treatment, and what can be done to prevent them. One last point the author would like to highlight is a mnemonic used by the U.S. Army. COLD is a good memory device for the use and care of cold weather clothing and footwear that can be used as the first line of defense against exposure to cold weather.