Epidemiological studies have been carried out to search for an influence of air conditioning on patterns of heat wave mortality in New York City. Two models were used to predict total daily summer mortality as a function of temperature; one of the models included heat acclimatization effects. Ratios of the models' predictions of heat wave mortality to actual mortality were calculated for heat waves occurring during 12 summers in the period 1949 to 1970. Trends in these ratios as a function of time were sought. The analysis suggests that the relative magnitudes of excess mortality during initial summer heat waves may have decreased over the 21-year period. No trend was observed for excess mortality during late summer heat waves.
