The Heat Health Warning System of DWD – Concept and Llessons learned

The Heat Health Warning System (HHWS) is a way to provide information for the general public and the public health authorities in order to be prepared for heat waves and to minimize their negative health impacts. The combination of weather forecast, thermal indices (Perceived Temperature) and their specific thresholds, short time acclimatization of people during summer conditions, nocturnal minimum temperature and indoor conditions are used to predict specific conditions such as heat episodes, which are associated with consequences like an increased mortality and morbidity among human population.

In addition information about the expected duration of these conditions is important. These specific thresholds and approaches have thermo-physiological bases and are used to assess the levels of heat stress to which humans are exposed. Warnings are generated from the numerical daily weather forecast and then confirmed or adjusted by the biometeorology forecaster. The HHWS can lead to a reduction of the heat related mortality and in general to protection of human life. The HHWS is in operation since 2005 and preliminary studies indicate a reduction in the heat related mortality ever since.