Societal attention to heat waves can indicate public health impacts

Both the frequency and intensity of hot temperature extremes are expected to increase in the coming decades, challenging various socio-economic sectors including public health. Thereby, societal attention data available in real time, such as Google search attention, could help monitor heat wave impacts in domains with lagged data availability. Here, we jointly analyze societal attention and health impacts of heat waves in Germany at weekly time scales. We find that Google search attention responds similar to hot temperatures as indicators of public health impacts; represented by excess mortality and hospitalizations. This emerges from piecewise linear relationships of Google search attention and health impacts to temperature. We can then determine temperature thresholds above which both attention and public health are affected by heat. More generally, given the clear and similar response of societal indicators to heat, we conclude that heat waves can and should be defined from a joint societal and meteorological perspective, whereby temperatures are compared with thresholds established using societal data. A better joint understanding of societal attention and health impacts offers the potential to better manage future heat waves.