CityAdapt Blog – PHASE: Public Health Adaptation Strategies to Extreme Weather Events

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Climate change models predict more frequent and more intense extreme weather events (EWE) for Europe in future decades. Great attention has been devoted to the health effects of high temperatures while the impact of other extreme weather events have been less investigated.

The recently concluded PHASE project, co-funded by the EU Commission Executive Agency for Health and Consumers (CHAFEA), provides a framework of tools for the preparedness and response to heat waves, cold, flooding, wildfires and synergies between EWE and air pollution events in order to reduce their impacts on health. A key feature of the PHASE project is the focus on public health. Tools provided within PHASE aim to improve prevention efforts and identify subgroups vulnerable to EWE in order to target prevention activities and optimize resources. The project includes public health institutions, research centers and universities from Finland, France, Greece, Hungary, Italy, Spain, Sweden and the United Kingdom.

Main findings from PHASE include:

  • A temporal variation in the effect of heat was observed in 9 EU cities (Athens, Barcelona, Budapest, Helsinki, Paris, London, Rome, Stockholm, Valencia) with a reduction in Mediterranean cities (adaptation) and an increase in Scandinavian cities (higher exposure) in recent years. Cold remains a relevant problem in all countries, with an increase in the impact in warmer areas which are not prepared. Cold prevention plans should include informative campaigns to raise awareness of risk, identification of at risk subgroups of people to actively monitor during winter and specific measures in energy and housing sector to address the indoor heating issue in winter. Susceptible subgroups may change over time and these need to be monitored to identify changes and account for emerging new at risk groups to whom prevention should be specifically addressed.
  • The synergistic effect of heat and high pollutant concentrations (ozone and PM10) was observed with a significant effect on health. It is important to develop integrated heat and air pollution warning systems and prevention measures should be activated especially during heat wave days with high levels of air pollution.
  • Wildfire smoke is more toxic than anthropogenic particulate matter. The synergy between the occurrence of forest fires and high PM concentrations has an effect on total, CVD and respiratory mortality.
  • The health effects of flooding are extensive and occur before, during and after a flood episode. Flooding impacts are both acute as well as medium and long-term. Surveillance indicators to monitor and assess the impact of flooding on health, and a health register protocol to improve preparedness and response to flooding were defined. Adequate planning and a multi-agency approach is required to effectively minimize the health effects.
  • Susceptible subgroups include: elderly, people with low socio-economic status, living in proximity to high risk areas, people suffering from chronic disease associated to each specific EWE. Children and pregnant women (risk of preterm delivery) were identified as being at greater risk to heat and air pollution.

PHASE provides a prevention framework of tools that provide knowledge on health risks associated to EWEs, and identify subgroups vulnerable to EWE in order to target public health actions and improve prevention efforts ( The uptake of this common approach will help maximize resources, improve adaptation and reduce the impact on health.

More information about PHASE can be found at

About the Authors: Francesca de’Donato, PHASE Coordinating Team, Paola Michelozzi PHASE Coordinator and Head of Environmental Epidemiology Unit, Department of Epidemiology, Lazio Regional Health Service ASL RME , Rome, Italy.