Mortality impact of extreme winter temperatures.

During the last few years great attention has been paid to the evaluation of the impact of extreme temperatures on human health. This paper examines the effect of extreme winter temperature on mortality in Madrid for people older than 65, using ARIMA and GAM models. Data correspond to 1,815 winter days over the period 1986-1997, during which time a total of 133,000 deaths occurred. The daily maximum temperature (T(max)) was shown to be the best thermal indicator of the impact of climate on mortality. When total mortality was considered, the maximum impact occurred 7-8 days after a temperature extreme; for circulatory diseases the lag was between 7 and 14 days. When respiratory causes were considered, two mortality peaks were evident at 4-5 and 11 days. When the impact of winter extreme temperatures was compared with that associated with summer extremes, it was found to occur over a longer term, and appeared to be more indirect.