What Does
Wind Chill Mean?
Wind chill refers to the way that wind speed can affect how cold the air feels against the skin. Measuring it is meant to provide a more accurate approximation of how we experience outdoor air, compared to gauging it based on temperature alone.
Wind chill is not considered an exact science. As such, the standards used to measure it can vary across different weather services.
Safeopedia Explains Wind Chill
Wind chill does not refer to the temperature of the air. Rather, it describes the feeling of air temperature on the skin when cool wind is blowing – the higher the wind speed, the colder the feeling is on the skin.
Formula to Calculate Wind Chill
Calculating wind chill involves measuring two parameters: air temperature and wind speed. A wind chill chart, like the following from the U.S. National Weather Service, is a simple way to determine whether outdoor workers are at risk of cold stress.
If a chart is not available, you can use a formula to calculate wind chill:
Wind chill (°F) = 35.74 + 0.6215T – 35.75(V0.16) + 0.4275T(V0.16)
Where:
T = air temperature in degrees Fahrenheit (°F)
V = wind speed in miles per hour (mph)
Since weather services in different areas use standards relevant to their region, there may be differences in estimation from weather services in other regions.
Cold Stress and Wind Chill
Cold stress does not get the same attention as heat stress, but it is nevertheless a serious problem that must be addressed whenever employees have to work in cold environments. Workers without sufficient protection from the cold can develop conditions like frostbite, hypothermia, and trench foot.
Employers will need to implement a number of different control measures to protect workers from cold stress. This will include scheduling additional breaks for employees to warm up when the temperature is low enough, along with deciding to put a pause on outdoor work entirely if the weather conditions become too extreme. When determining how cold is too cold for workers to be safe, employers must factor in the wind chill.
For instance, working in –25°F (-31°C) weather might be tolerable so long as everyone is dressed warmly. If the winds exceed 20 mph (32 km/h), however, the wind chill will significantly elevate the risk of cold stress.
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