Against the silent danger: Heat protection – a task for us all

Climate change is increasingly manifesting itself in the form of more frequent, intense and prolonged heatwaves. While there was an average of 4.2 hot days per year between 1961 and 1990, this figure doubled to 8.9 hot days per year in the subsequent period from 1991 to 2020. According to the meteorological definition, a day is considered a hot day if the maximum daily temperature reaches or exceeds 30°C. The number of tropical nights, defined as nights with temperatures above 20°C, has also increased in many places in recent years. These effects of climate change pose a growing health risk – especially in heavily sealed and densely built-up urban areas where the “heat island effect” can have a very dramatic impact. Older people, young children, the chronically ill and socially disadvantaged population groups are particularly vulnerable to these extreme weather events.

According to estimates by the Federal Environment Agency (UBA), several thousand heat-related deaths have been recorded in recent years. Furthermore, the economic impact of heatwaves has received little attention to date: they can reduce human productivity, increase energy consumption and thus energy costs (e.g. due to the need to cool products) and, according to the German Institute for Economic Research (DIW), even damage infrastructure. Yet despite these experiences, the heat seems to catch many German cities unprepared every year, and the danger posed by heat is hardly present in the collective consciousness. These developments highlight the urgent need for future action: as key players in the provision of public services, municipalities have a responsibility to establish protection and prevention structures – even if health-related heat protection is not (yet) a municipal duty in the strict sense.

Municipalities have numerous established knowledge resources at their disposal. Health-related heat prevention is by no means unchartered territory within climate adaptation. In Germany, there are over 40 municipal heat action plans (HAPs) that cities and regions use to prepare and coordinate various measures. And international role models such as France show just how effective standardised processes and structured communication can be. Significant progress can be made with minimal effort, particularly in the risk and health communication areas, as well as through raising awareness among population groups, social institutions and multipliers – provided that the measures are consistently tailored to the specific needs of vulnerable groups.

At the same time, however, there is considerable discrepancy between the need for action identified in municipalities and the actual state of implementation. This implementation gap is the result of various factors: on the one hand, voluntary measures require a high degree of political will and intrinsic motivation from those actors involved within local government; on the other hand, external partners such as welfare organisations, care facilities and civil society initiatives are crucial for accessing particularly vulnerable target groups. For a long time, public debate in Germany focused primarily on structural and technical measures for climate adaptation. These measures to expand green and water areas in urban areas, such as creating and securing green spaces, green roofs and facades, planting street trees, unsealing concrete surfaces and providing shade in public spaces, are essential for the long-term and sustainable transformation of towns and cities. However, planning and implementing them is often lengthy, costly and complex. A one-sided focus on these measures can be discouraging, particularly for smaller municipalities with limited resources. This makes low-threshold, communicative and awareness-raising measures, such as those successfully practised in France for over 20 years, all the more important.

This is precisely where municipal heat action plans (HAPs) serve a valuable purpose: they enable structured coordination, pool existing expertise and primarily address short-term, behavioural prevention measures. They raise awareness about heat and the danger it poses among all those involved, analyse risks and impacts, establish effective support structures and improve planning through tailored heat protection measures. In addition to disseminating information and deploying warning systems, such as the one provided by the German Meteorological Service (DWD), procedural and emergency plans such as municipal reporting chains also play an important role in preparing and protecting the population (in terms of health). Implementing long-term, situational prevention approaches – such as heat-resilient planning and construction – remains the responsibility of overarching climate adaptation strategies and interdepartmental planning within municipalities.
Effective heat-related health prevention requires a combined approach to two aspects: the structural (situational prevention) and individual (behavioural prevention) dimensions. In concrete terms, this dual strategy means that urban development measures such as unsealing, greening and creating cool public spaces must be promoted. Also required, however, are formats that are effective in the short-term for providing health education, early warning systems and directly communicating with vulnerable population groups, such as heat hotlines, neighbourhood networks and heat guides.

Since the heatwave in 2003, France has been considered a role model, as heat is also understood there as a social risk. There are structured reporting chains that link mandatory measures to the warning levels issued by the national weather service. At that time, around 15,000 people died in France as a result of the heat. It was two factors – ignorance and isolation – that made the effects of the heat so devastating: ignorance of the dangers of heat and the isolation of vulnerable groups. The heat-related deaths were seen in France as a social catastrophe, a collective failure. Since the introduction of the national heat plan in 2004, a multi-level warning system has been in place from June to mid-September, meaning that fire brigades and hospitals are now better prepared for increased call-outs and patient numbers during heatwaves.

However, many of these approaches cannot be easily transferred to German conditions – particularly due to the federal structure and the distribution of responsibilities between the federal government, federal states and the municipalities. Nevertheless, the French experience can provide valuable insights for developing municipal strategies in Germany, as set out in Difu’s “Heat Action Plans in Municipal Practice” publication in the form of concrete recommendations for action.

The good news is that many municipalities have already embarked on this path. The first frontrunners are setting an example and continuously developing practical solutions. In recent years, cities such as Karlsruhe, Düsseldorf, Dresden, Duisburg, Mannheim and Cologne have demonstrated how heat protection and effective measures can be implemented by collaborating across the environmental, health, social affairs, urban planning, green spaces and climate adaptation spheres. The field of health-related heat protection is evolving – it is dynamic, receptive to learning and increasingly networked. The challenge, however, is too great for municipalities to tackle alone. This area needs to be more firmly embedded in everyday social life, administration, politics and civil society. Health-related heat protection is not just the public sector’s responsibility – it requires solidarity, shared responsibility and a new approach to care in light of the climate crisis. Protection from heat begins in the neighbourhood, in the community, in personal contact – and it can only succeed if everyone plays their part.

Pre-publication from Difu’s Berichte magazine, issue 3/2025.