As climate change fuels more frequent and severe heat waves, governments worldwide have adopted Heat-Health Action Plans (HHAPs) to prevent illness and death from heat stroke, heart attacks, and other unwanted physical and mental health outcomes. Yet a new study by researchers at Columbia University Mailman School of Public Health reveals a critical gap in these plans: while most acknowledge mental health risks, such as heightened anxiety, depression, and suicide, few propose concrete interventions to protect vulnerable populations.
According to one estimate , exposure to heatwaves globally has doubled since the 1980s.
The study, the first to systematically assess mental health inclusion in HHAPs worldwide, analyzed 83 plans across 24 countries. While most (75.9 percent) acknowledged mental health broadly, only 31.3 percent specified heat's unique mental health impacts, like increased psychiatric emergencies or suicide risk. Worryingly, just 21.7 percent of HHAPs analyzed outlined concrete interventions, despite evidence that heat worsens outcomes for people with conditions like depression and schizophrenia while triggering new mental health crises. The findings are published in the journal Current Environmental Health Reports(link is external and opens in a new window) .
"We are seeing increasing evidence on negative effects of extreme heat on mental health," says the study's senior author Robbie Parks , PhD, assistant professor in the Department of Environmental Health Sciences at Columbia Mailman School. "Yet when it comes to planning for extreme heat, there is a gap between acknowledging mental health as a concern and identifying interventions to address it."
Many HHAPs failed to address underlying drivers like heat-induced displacement, economic stress, or sleep disruption and focused on broad measures like public messaging rather than targeted support. For instance, few addressed at-risk groups like homeless individuals or proposed community-based strategies—such as neighbor check-ins—that could reduce isolation during extreme heat events. Notably, India was alone among low- and middle-income countries in addressing mental health, despite these regions facing disproportionate heat risks.
"People with mental health conditions face compounding barriers during heatwaves," explains lead author Allison Stewart-Ruano, a doctoral candidate in environmental health sciences at Columbia Mailman School. Stewart-Ruano emphasizes the need for multi-level interventions, such as ensuring cool sleeping environments or training communities to support vulnerable neighbors. "Effective plans must bridge clinical and community approaches, combining medical care with social cohesion strategies that reduce isolation during extreme heat events."
Additional co-authors include Raenita Spriggs, Katherine M. Keyes, and Yoshira Ornelas Van Horne at Columbia Mailman School; Alessandro Massazza at the London School of Hygiene and Tropical Medicine; Alexandra Czerniewska at Health Equity and Human Rights LLP; and Alejandro Saez Reale and Joy Shumake-Guillemot at WHO/WMO Joint Office for Climate and Health.
The study is funded by grants from the National Institutes of Health (ES007322, ES033742, AG093975, MH128734).
The authors declare no conflicts.
