Heat waves and heat warnings in cities:
Urban dwellers are more affected by heat waves, which will occur more frequently, more intensively and will last longer as a result of climate change, than rural dwellers. The buildings in cities that are heated during the day cool down less at night than buildings in less densely populated areas. This places additional demands on the body‘s already stressed thermoregulation system and shortens rest periods at night.
In this way, persistently high temperatures have a particularly stressful effect on the human body. In Germany, around 7600 people died in 2003 as a result of heat-related health problems. The heat warning system of the German Meteorological Service has established itself in order to be able to react in time to impending heat waves and to initiate measures for health protection.
Since 2017, the specific heat stress in cities due to the Urban-Heat-Island effect has been given special consideration in heat warnings. Studies in Berlin and Brandenburg have revealed that during the heatwave in 1994 the highest deviation of mortality from the expected value occurred in the most densely built-up areas of Berlin. In order to be able to deal with the more intense heat waves in the future and to avoid health risks, adaptation measures should therefore be developed, especially in urban areas.