windchill factor [AS, wind, air, cele, cold] , the amount of chilling of the body, beyond that resulting from a cold ambient temperature, because of exposure to cool air currents. The windchill factor is expressed in degrees Celsius or Fahrenheit as the effective temperature felt by a person exposed to the weather. Because windchill factors are based on exposure of dry skin to cool air currents, air blowing at the same speed over a wet skin surface would cause additional loss of body heat and a greater windchill.