As the winter draws closer, and temperatures dip below freezing, we focus employee safety on the seasonal changes. Body heat can be lost by workers in cold environments simply by breathing cold air. Direct skin exposure to the cold air or water is the most common means that heat is lost from the body. Full immersion in water can cause heat loss 25 times faster than exposure to cold air, at the same temperature. It is important to educate employees working in cold environments on the dangers of cold weather stress and what they can do to protect themselves.
Hypothermia can begin to onset when your body loses heat faster than it can generate it. This is when the core body temperature falls well below normal levels. We normally consider an adjustment of environmental temperatures of several degrees to be normal. Some days, temperature highs and lows can swing 20-30 degrees. But when our body experiences a change in core temperature of just a few degrees, the result can be disastrous. A change from normal body temperature from 98.6°F to 95°F is considered the beginning stages for onset of hypothermia. Once the temperature reaches as low as 85°F, it is categorized as severe hypothermia, and can quickly become fatal.
With this onset, the body begins to compensate and find ways to increase core temperatures, usually by shivering or other ways to increase blood flow. The individual will also feel tired, clumsy, and confused. If no change is made in conditions to increase the core temperature, the shivering will stop as the body then starts to reserve energy. The heart rate and breathing is drastically reduced and the victim can easily lose consciousness as a result.
Because hypothermia can be extremely dangerous if not treated immediately, employees should be trained to identify the signs and symptoms and appropriate first aid steps. The first key is moving them to a warmer environment. This may be indoors or in a heated vehicle. If they have any wet clothing on (which causes a much more rapid heat loss), this should be removed. It is our instinct to try to warm hands and feet first, but it is really the body’s head and torso that needs to warm up first. Warm beverages may help, but this is not a permanent or stand-alone solution. If necessary and available, wrap the victim in a blanket which also covers the head and neck. If the victim is approaching severe hypothermia, you will need to seek medical attention as soon as possible.
Solutions for combating cold weather can range in effectiveness depending on the working conditions. Engineering controls such as radiant heaters or wind shields can be used to protect a number of employees all at the same time. Effective work practices include planning work during the warmest parts of the day and drinking warm liquids (non-caffeinated, non-alcoholic). Taking breaks in heated areas and eating high calorie are other good preventive work practice measures.
The single most important factor for employees who cannot avoid the cold weather is utilizing protective clothing. This includes wearing at least three layers of clothing; an inner layer to keep moisture away from the body, an insulating layer, and a wind/water resistant outer layer. Hats and hoods will protect from heat loss in the head, especially for employees wearing hard hats. Gloves and insulated socks can prevent heat loss in the extremities. Tight fitting, non-wicking inner layers of clothing will typically not allow perspiration to evaporate, and holds the cold wet clothing close to the body, increasing heat loss.
Cold weather work will always be a fact of life for most industries. It is important for companies and safety departments to educate the staff on how to protect themselves and how to identify signs and symptoms. Environmental and work practice controls can be used, but generally must be implemented by field supervision. In either case, everyone should be aware of the dangers of cold stress such as hypothermia and how to identify and protect themselves. Before we know it, the temperatures will be on the rise and we will be back in the summer, discussing the effects of heat stress.
Related Topics: Hypothermia, Safety Articles, Monthly Safety Topics