POLICY BRIEF

Addressing Direct and Indirect Health
Impacts of Temperature Extremes

Temperature extremes – heatwaves and cold spells – are increasingly frequent, severe, and prolonged due to climate change, with direct and indirect health impacts. These include heat-related illnesses, cardiovascular and respiratory stress, dehydration, and hypothermia, alongside exacerbation of chronic diseases. Mental health outcomes are also affected, with evidence linking extreme heat to heightened anxiety, depression, substance use, and increased rates of self-harm and suicide. Vulnerable populations, including older adults, children, outdoor workers, unhoused individuals, and those with pre-existing medical or mental health conditions, are disproportionately affected. Achieving Sustainable Development Goal (SDG) 3 (Good Health and Well-Being) and fulfilling commitments under the Paris Agreement require multisectoral adaptation and mitigation strategies that integrate climate resilience into health systems, community design, and emergency response. This Fast-Track Health policy brief highlights best practices through five case studies, discusses challenges and opportunities, and provides actionable recommendations for municipal, national, and regional health authorities.

National Heatwave Plan Post-2003 in France: Following the 2003 European heatwave, which caused over 14,000 excess deaths in France, the government developed a multi-tiered National Heatwave Plan (Plan Canicule) combining real-time meteorological alerts, targeted outreach to vulnerable groups, and healthcare readiness measures. Regular updates have incorporated climate projections, public awareness campaigns, and neighborhood check-ins for isolated individuals. This approach has significantly reduced heat-related mortality during subsequent events, demonstrating the value of early warning systems coupled with local action. (International Archives of Occupational and Environmental Health, 2006)

Ahmedabad Heat Action Plan in India: Ahmedabad became the first South Asian city to implement a city-wide Heat Action Plan in 2013, integrating early warning systems, public cooling centers, and worker safety protocols. Partnerships between the municipal government, health sector, and NGOs ensured targeted outreach to slum communities, where heat risks are highest. Evaluations have shown reductions in heat-related deaths and increased public awareness, providing a scalable model for other heat-prone urban areas. (Health Affairs, 2014)

New York City Cool Neighborhoods Program in the United States: Launched in 2017, Cool Neighborhoods NYC focuses on tree planting, reflective rooftop coatings, and community engagement to reduce urban heat island effects. It also deploys neighborhood-based outreach teams to check on vulnerable residents during heat events, integrating social services and mental health support. The initiative has been credited with both cooling microclimates and fostering resilience in low-income neighborhoods disproportionately impacted by heat. (New York City Environmental Protection, 2019)

Bushfire Smoke and Heatwave Mental Health Impacts in Australia: During the 2019-2020 Australian bushfires, extreme heat compounded air pollution exposure, leading to spikes in respiratory illness, cardiac events, and mental health distress in affected communities. The integration of mental health crisis response into emergency services, along with mobile counseling units, helped address trauma and anxiety among residents. This highlights the necessity of including psychological support in climate-related disaster response. (The Lancet Planetary Health, 2020)

Cold-Weather Preparedness and Mental Health Awareness in Finland: Finland’s cold-weather preparedness framework includes public advisories, home insulation support, winterized public transport, and mental health awareness campaigns targeting seasonal affective disorder (SAD). Collaboration between meteorological services, healthcare providers, and municipalities ensures rapid mobilization during cold spells, mitigating hypothermia risk and supporting psychological resilience in winter months. (Journal of Affective Disorders, 1998)

One major challenge is the increased frequency and intensity of extreme temperatures outpacing current adaptation measures. Health systems often lack dedicated climate-health surveillance, leaving gaps in timely detection of temperature-related morbidity and mortality. Mental health impacts remain under-addressed in emergency preparedness, despite growing evidence of their severity. Vulnerable populations – such as migrants, rural residents, and informal settlement dwellers – may not be reached by conventional alert systems or may lack access to cooling or heating resources. Additionally, structural inequalities mean that low-income communities often reside in areas with less green space, more heat-retaining infrastructure, and inadequate housing insulation, amplifying health risks.

There is a growing opportunity to integrate temperature resilience into public health planning, urban design, and mental health services. Cities can invest in nature-based solutions – such as urban forests, green roofs, and water features – that reduce ambient temperatures while providing co-benefits for air quality and well-being. Technological advances in climate modeling can improve accuracy and lead time of extreme temperature alerts, enabling earlier and more targeted interventions. Embedding mental health services into heat and cold emergency responses can improve both short- and long-term health outcomes. Partnerships across health, housing, environment, and labor sectors offer a pathway to equity-focused resilience, ensuring all communities, regardless of income or geography, can withstand and recover from temperature extremes.