Extreme heat may raise suicide risk by disrupting sleep, emotional control: Study

A World Bank and Georgetown University study links extreme heat to higher suicide risk, highlighting the lesser-known effects of climate change on the mental health of millions.

In Short

• Study in Bangladesh found suicide risk rises at temperatures of 28-35ºC
• Poor sleep accounts for nearly 30% of heat-related suicide risk at 35ºC
• Vulnerable groups include poorer, less educated and summer months

Extreme heat, becoming increasingly common in India and around the world, could do more than take a physical toll on the human body.

Climate-induced heat could also affect mental health, increasing suicide risk by disrupting sleep and making it harder to manage emotions, a new study by the World Bank and Georgetown University has found.

Published in Environmental Research, the study examined how rising temperatures are potentially associated with suicide risk in Bangladesh, a country particularly vulnerable to climate change.

The researchers stressed that the findings point to possible pathways linking heat and suicide risk, rather than establishing that high temperatures directly cause suicide.

Researchers found that the risk began to rise at temperatures of 28°C and was highest at 35°C.

The findings provide another look into how climate change could affect mental well-being, particularly in countries where millions face prolonged exposure to extreme heat and have limited access to cooling.

“Extreme heat events are becoming more frequent, longer, and more intense due to climate change,” said lead author Syed Shabab Wahid, an assistant professor at Georgetown University and a World Bank researcher.

HOW HEAT AFFECTS SLEEP AND EMOTIONS

The study followed 7,492 people across two rounds of a nationally representative survey in Bangladesh. Researchers examined suicide risk alongside exposure to high temperatures, sleep quality and the ability to regulate emotions.

At 35°C, poor sleep accounted for 29.5% of the observed association between heat exposure and suicide risk. Difficulties in regulating emotions accounted for another 1.8%.

Wahid explained that “high ambient temperatures can impair restorative sleep patterns.”

Heat can also weaken a person's ability to manage difficult emotions and cope with psychological distress.

Sleep is essential for the brain and body to recover. But as India experienced this year, warmer nights are making it increasingly difficult to get adequate rest. When nights remain hot, people may struggle to sleep well, leaving them tired and less equipped to deal with everyday stress.

“Without identifying how ambient heat disrupts daily physiological functions and emotional control,” Wahid said, public health officials and clinicians face limitations in developing targeted interventions.

RISING TEMPERATURES, RISING MENTAL HEALTH RISKS

The association between extreme heat and suicide risk was stronger during summer and among poorer and less educated populations, highlighting how social and economic conditions can influence vulnerability.

Wahid said the research could help health agencies “monitor heat waves alongside sleep quality disruption indicators” to identify when preventive support may be needed.

He also called for “sleep preservation, household cooling access, and community-based emotional regulation training” as potential interventions during heatwaves.

Looking ahead, researchers want to explore affordable cooling solutions, better-designed homes and ways to protect people from heat during the night.

“This line of research can integrate mental healthcare into national climate resilience planning and early warning systems,” Wahid said.

- Ends