Figure 2.

Effects of the heat wave warning system on all-cause mortality based on the comparison of mortality changes due to heat wave alert announcements for heat wave days versus non-heat wave days (i.e., counter factual) in 2009–2014 (mortality per 1,000,000 people per day). The effects are the estimates of difference-in-differences (DD) that were obtained by comparing mortality due to heat wave alert announcements for heat wave days versus mortality for non-heat wave days (i.e., counterfactual) through the difference-in-differences analysis. Negative estimates indicate reduction in mortality due to the heat wave alerts.