Heat-related deaths

Heat-related deaths in Switzerland have been reported annually since 2023. The impact indicator "heat-related deaths" also includes retrospective deaths for the years 2000-2022. This activity is conducted as part of the federal government's climate change adaptation strategy.

Temperatures are rising worldwide due to climate change. Switzerland is also affected: The last ten years have been 2.5°C warmer than the pre-industrial average. The higher average temperatures are accompanied by significantly more hot days and tropical nights in summer. These high temperatures can put a strain on human health and lead to death.

Until 2023, the Federal Office of Public Health (FOPH) and the Federal Office for the Environment (FOEN) only analyzed the effects of heat on deaths in Switzerland in individual, particularly hot summers such as 2003, 2015, 2018 and 2019.

However, as heat stress is expected to increase in the future, the federal government will monitor heat-related deaths on an annual basis starting in 2023. The "heat-related deaths" impact indicator is published by the FOEN as part of the federal government's "adaptation to climate change" strategy and the associated action plan.

The following federal offices use this indicator for their reporting: Federal Office of Public Health, Federal Office for the Environment and Federal Office for Civil Protection. These federal offices developed the methodology the analysis of the indicator together with the Federal Office of Meteorology and Climatology and the Federal Statistical Office.

The impact indicator uses the method of attributable case calculation. This involves linking the measured mean daily temperatures and an exposure-impact relationship, which describes the connection between temperature and mortality, with the observed mortality. Explanations of the methodology can be found directly on the website of the indicator and in the report attached below.

The indicator shows the number of deaths that can be statistically attributed to the three temperature ranges (daily mean temperature Tmean): moderately hot (Tmean from optimum temperature and less than 25°C), hot (from 25°C and less than 27°C) and very hot (from 27°C). Regional differences in heat stress are taken into account. In addition, heat-related deaths are estimated separately for two age groups (<75 years and ≥75 years), by gender and for the seven major regions.

Climate change will lead to an increase in the frequency and intensity of heat waves and heat days. At the same time, there are more and more vulnerable people due to demographic change. Measures to protect health from heat are therefore becoming increasingly important. On behalf of the FOPH and FOEN, Swiss TPH is conducting a research project on the status of implementation of adaptation measures as well as their impact on the increasing heat stress in the health sector.

Synthesebericht: Hitzebedingte Todesfälle (SwissTPH, 2023) im Auftrag von BAFU und BAG (PDF, 2 MB, 21.02.2024)This report is only available in German.

Climate indicator: Heat-related deaths

Der Bund erfasst hitzebedingte Todesfälle

Available in German, French and Italian.