ET = equivalent temperature (degrees Celsius)
WCF = wind chill factor (Watts per square metre)
SQROOT = square root function
W = wind speed (Km/hr)
T = air temperature (degrees Celsius)
(Source: Weather University of Waterloo)
'Our loyalties are to the species and the planet. We speak for Earth. Our obligation to survive is owed not just to ourselves but also to that Cosmos, ancient and vast, from which we spring.'