Advances in technology, along with a poorly understood and regionally inconsistent wind chill program in Canada underlined the need for assessment and renewal. The process began with a national survey and a literature review, followed by an International Internet Workshop on Wind Chill in April 2000 leading to bilateral collaboration between Canada and the USA. Subsequently, new research and modeling techniques, complimented by human trials on healthy volunteers during May and June of 2001, led to the development of a new wind chill index and a new operational forecasting program implemented in October 2001. At the same time a modest but successful public education program was developed and implemented for the official fall 2001 launch of the updating and standardizing of the wind chill index used by the Meteorological Service of Canada (MSC) and the US National Weather Service (NWS).

Large variations in the climate of the different regions of Canada made setting warning levels problematic, especially after observing much variability in individual response to wind chill during the human trials. Accommodation was made, with regard to human adaptation, - behavioural and physiological - to local climate regimes. The media and the general public required an enhanced understanding of the impact of wind chill so another problem addressed was the use of “minutes to freeze” included in warning messages. Since individual variability was shown to be quite high, the decision was made to focus on the more vulnerable proportions of the population. This most vulnerable portion is based on the most susceptible 5% from the human trials. Accordingly, new procedures for forecast and reporting operations were implemented and a public education program tailored to address these aspects.

A review of the first winter of operation of the renewed wind chill program undertaken in the spring of 2002 along with further human trials will allow for further refinement of the minutes to freeze and its customization for the different climatic regimes of Canada. If information of the effect of wind chill on infants, children and the elderly becomes available, it too will be incorporated into the wind chill program.