Heat Health Risk Assessment

About the Heat-Health Risk Assessment Tool

Developed within the SDGs-EYES Horizon Europe project, this tool contributes directly to SDG 13 - Climate Action, enhancing local capacity to monitor and respond to heat-related health risks in a changing climate.

The tool is designed to help decision-makers and practitioners understand and address the health impacts of climate change among people aged 65 and over in the city of Turin. It integrates data on climate hazards, population exposure, and social, clinical, and environmental vulnerability to provide a comprehensive picture of where and why older adults are most at risk during heat events — at the micro-area level (census tract, the smallest spatial unit in the city of Turin). Through an interactive map, users can explore how different vulnerability factors — such as age, chronic diseases, social isolation, housing and environmental quality, and access to health and social services — influence heat-related health risks across urban neighborhoods. By hovering over a census tract, dynamic charts display:

The macro-factors contributing to risk in that area (pie chart)
the main determinants of vulnerability and their relative contribution to overall risk (bar chart)

Helping users identify both the drivers of fragility and the policy sectors involved (health, environment, social care, and urban planning).

The tool supports evidence-based decision-making by providing actionable insights for:

Prioritising adaptation and mitigation measures in high-risk areas
Informing public health preparedness and urban resilience strategies
Strengthening intersectoral collaboration across local institutions

Methodology

The Heat-Health Risk Assessment follows the IPCC risk-based framework, where Risk = Hazard x Exposure x Vulnerability. In this model:

Hazard represents the intensity and frequency of extreme heat events
Exposure identifies the population potentially affected (people aged 65+ in Turin)
Vulnerability reflects the demographic, social, health, and environmental factors that increase or reduce susceptibility to heat stress.

Each census tract's overall Heat-Health Risk Index results from combining these three components after standardizing all indicators (min-max normalization, 0-1 range) to ensure comparability across variables.

About Vulnerability Indicator Weighting

The set of vulnerability indicators is grounded in scientific evidence on how demographic, social, health, and environmental factors influence heat-health risks.

Since each factor contributes differently to health outcomes, assigning equal weights would misrepresent their true relevance.

Weights were determined through a mixed, evidence-based approach that integrates both expert judgment and epidemiological validation:

Stakeholder survey (AHP method): Experts and local stakeholders ranked the relative relevance of 26 indicators for elderly heat vulnerability.
Epidemiological validation: Results were cross-checked with summer mortality data from the Turin Longitudinal Study (SLT), estimating the fraction of deaths attributable to each vulnerability factor.

The resulting normalized weights (0-1) were used to calculate the composite Heat-Health Risk Index, providing a more realistic and data-driven representation of vulnerability across urban areas.