The impact of the 2003 heat wave on mortality in Shanghai, China

In 2003, Shanghai recorded the hottest summer in over 50 years. We investigated the impact on the mortality of a heat wave in 2003 in Shanghai. We calculated excess mortality and rate ratios (RRs) during the heat wave (July 19–August 6, 2003) compared to a reference (non-heatwave) period (June 28–July 9, and August 16–August 22). During the heat wave, the RR of total mortality was 1.13 (95% CI: 1.06–1.20), and the impact was greatest for cardiovascular (RR = 1.19, 95% CI: 1.08–1.32) and respiratory (RR = 1.23, 95% CI: 1.02–1.48) mortality. Gender did not make a statistically significant difference for the heat-wave impact. Elderly people (over 65 years) were most vulnerable to the heat wave. Our analysis showed that the 2003 heat wave had a substantial effect on mortality in Shanghai. Public health programs should be implemented to prevent heat wave-related health problems in the city.