Patient Resources
Get Healthy!
Heatwaves Raise Hospital Admissions For Mental Health Woes
- July 14, 2026
- Ernie Mundell HealthDay Reporter
TUESDAY, July 14, 2026 (HealthDay News) — Heatwaves are increasing in severity and duration for Americans, and research suggests they leave a rise in mental health crises in their wake.
A new international study tracked more than 2.6 million warm-season hospital admissions across Brazil, Canada, Chile and New Zealand from 2000 through 2019.
Researchers found a 3.3% rise in hospitalizations for mental health issues on the day of a heatwave. That caseload rose over the following eight days to a cumulative 5.6% increase in such admissions compared to non-heatwave periods.
“These findings indicate that prolonged extreme heat can acutely increase mental health-related hospital demand and support targeted preparedness during severe heatwaves,” said study co-author Dr. Yuming Guo. He is a professor of global environmental health and biostatistics at Monash University in Melbourne, Australia.
Rates of hospital admission during a heatwave spiked by 22.9% for those with anxiety disorders; 21.7% for people with personality disorders; 8.2% for people diagnosed with schizophrenia; and 7.2% for those struggling with substance abuse issues.
The young (people under the age of 20) and the elderly were more likely to be affected, the study found.
Why the rise in admitted cases during heatwaves? Guo and colleagues suspect that — especially for those without air conditioning — poor sleep and stressed days could account for the trend.
"This stress response can heighten irritability, anxiety and cognitive impairment, particularly among individuals with pre-existing mental disorders," the authors wrote.
With global warming continuing, the problem is likely to get even worse, Guo said.
Climate change “has emerged as a pressing factor influencing mental health on a global scale, with extreme weather events, resource scarcity and ecosystem disruptions amplifying psychological stress and mental health risks," he said in a Monash news release.
The authors said all of this points to a "need for tailored public health interventions to mitigate heatwave-related mental health risks."
The study was published July 10 in Nature Health.
More information
Get tips on keeping your cool during a heatwave at the World Health Organization.
SOURCES: Monash University, news release, July 10, 2026; Nature Health, July 10, 2026
