Excess Injury Mortality in Washington State During the 2021 Heat Wave

Objectives. To determine whether the 2021 Pacific Northwest heat wave resulted in excess injury (both unintentional and intentional) deaths. Methods. With US death certificate data from December 29, 2013, to July 31, 2021, we generated weekly counts of injury deaths in Washington State and the rest of the country. We used time-series methods to identify excess injury deaths that may have occurred during and following the anomalously warm temperature period based on those expected from history and from simultaneous deaths in the remainder of the United States. Results. Beginning the week including June 25, 2021 (heat wave initiation), 3 weeks exceeded the expected count of injury deaths in Washington State, with an estimated total of 159 excess injury deaths (95% detection interval5122, 195) during the 3-week period. Conclusions. The 2021 Pacific Northwest heat wave was associated with an increase in injury deaths. Public Health Implications. Under global warming scenarios, heat waves of this magnitude will become much more common. Adaptation and planning efforts are needed to protect residents of the historically temperate Pacific Northwest for a range of health outcomes.