Wind chill or windchill is a perceived decrease in air temperature felt by the body on exposed skin due to the flow of air.
It is also a phenomenon in which the passing-flow of low-temperature air lowers the temperature of the body. In other words, cold wind feels cold not only because the ambient temperature is cold but also because it strips heat away from the body.
What Is Wind Chill and How Does It Affect the Human Body?
The concept behind wind chill and wind chill index is simple: Wind does not change the ambient temperature, but it strips heat away from heat-producing objects such as the human body. For humans and other animals, exposure to cold wind changes the perception and experience of outside temperature.
A particular weather report for a given time of the day would indicate that it is 55 degrees Fahrenheit outside. For some, this temperature can be bearable with an appropriate level of clothing. However, stepping outside can feel a lot colder because of the wind.
Remember that wind chill is also a phenomenon in which heat leaves the body. The second law of thermodynamics states that heat would naturally and spontaneously flow from a hotter system to a cooler system until both systems reach the same temperature or thermal equilibrium.
Humans and other animals are also susceptible to heat loss due to the second law of thermodynamics. However, the heat transfer from the body and to the surrounding environment also causes a thin layer of warmer air molecule to build around. This layer provides mild insulation that decreases the rate of heat loss.
Cold wind speeds up how heat moves from one system to another. For humans exposed to cold wind or placed in a windy environment, the layer of warm air molecules gets blown away and replaced by cold air molecules.
The human body always tries to maintain a consistent internal temperature. Exposure to cold temperature and windy environment drives the body to produce more heat. However, cold wind draws heat away from the body faster. The faster the heat is transferred away from the body, the colder the body feels. Wind chill makes the body feel colder than the actual temperature outside.
What Is The Wind Chill Index?
Similar to the heat index, the wind chill index or wind chill factor has been referenced to provide communities and individuals with an idea of the possible health-related risks associated with cold ambient temperature and cold wind.
Nevertheless, the wind chill index is a measurement expressed in numerical value. This measurement accounts for both the temperature of the air and how fast the wind is blowing. Note that faster wind results in quicker heat loss.
It is important to keep in mind that perception toward wind chill can be subjective. In addition, the wind chill index is not a definite temperature measurement. The resulting values are merely rough estimates because there is no way to specifically measure the temperature related to the wind chill phenomenon.
However, despite the fact that wind chill is a subjective phenomenon brought by personal perception and experience about the outside temperature, the wind chill index is still used in public advisories to give individuals an idea about their susceptibility to frostbite or hypothermia.
