Serious consequences of cold stress, including hypothermia, frostbite, and trench foot, can occur at surprisingly moderate temperatures. Custodians, maintenance workers, teachers and other staff who must work outside, or in cold environments such as walk-in refrigerators and freezers, need to be aware of the dangers and how to protect themselves.
Four factors contribute to cold stress: cold temperatures, high or cold wind, dampness, and cold water. In addition, certain medications, such as those for anxiety, depression or nausea, and certain conditions, including low thyroid hormone, diabetes and even being underweight, can increase susceptibility to cold.
When most people think of hypothermia, they think of frigid temperatures or blizzard-like conditions. Actually, hypothermia occurs most often in the spring and fall, rather than winter.
When in a cold environment, most of the body’s energy is used to keep the internal temperature warm. The body will shift blood flow from the extremities and outer skin to the core (your chest and abdomen). If the body loses heat faster than it can be produced, core temperature will fall. Hypothermia occurs when the core body temperature falls below 95° F. The person begins to shiver and stomp feet in order to generate heat. As the body temperature continues to fall, serious symptoms and even unconsciousness and death can occur.
Low body temperature can affect the brain, making the victim unable to think clearly or move well. This makes hypothermia particularly dangerous, because the victim may not know it is happening and so may do nothing to protect himself or herself. Signs & Symptoms
As heat is drawn from skin to core, exposed skin can cool rapidly. Frostbite occurs when the skin actually freezes and loses water. While frostbite usually occurs when the temperature is 30° F or lower, wind chill factors can allow frostbite to occur in above freezing temperatures. Frostbite typically affects the feet and hands. Signs & Symptoms
Trench foot, or immersion foot, is caused by having feet immersed in cold water for long periods of time. It is similar to frostbite, but considered less severe. Signs & Symptoms
As wind increases, it draws heat from the body, driving down skin temperature and eventually the core body temperature. Therefore, the wind makes it feel much colder. For example, when the air temperature is 5° F, and the wind speed is 35 mph, your exposed skin experiences conditions equivalent to the air temperature being -21° F. At this wind chill temperature, exposed skin can freeze in 30 minutes. As the chart shows, frostbite can occur after 30 minutes exposure to temperatures as high as 40 F and wind speed as low as 5 mph.
You and your UniServ Representative can seek protective contract language to ensure that the following measures are in place:
Appropriate protective clothing is the most important protective measure.
A detailed discussion of hypothermia and cold weather injuries: www.princeton.edu/~oa/safety/hypocold.shtml
Details on hypothermia: www.cdc.gov/niosh/topics/coldstress/#_Hypothermia