In a Heat Wave, Schizophrenia Is So Much Deadlier Than Any Other Medical Condition

In June 2021, a record-breaking heat wave struck Vancouver, Canada, with temperatures soaring past 102 degrees Fahrenheit. The city's ER, St. Paul's, was overwhelmed as a surge of patients with heat-related illnesses arrived. Paramedics lined the hallways, unable to respond to emergency calls due to a lack of beds—a situation known as a "bed block." Dr. Yoo, the ER doctor featured in this story, experienced an adrenaline rush as he treated numerous patients with heat-related illnesses.

People with schizophrenia, a mental illness often associated with Vancouver's Downtown Eastside, were disproportionately affected by the heat wave. They constituted 16 percent of the more than 600 heat-related deaths across British Columbia that week, and during a heat wave in Montreal in 2018, they made up 26 percent of fatalities.

The root cause of these deaths lies in the physiological differences between people with schizophrenia and those without the disorder. Their bodies regulate temperature differently, and those on medication may experience even more significant challenges in managing their body heat. This makes them particularly vulnerable to heat-related death, a risk that no other chronic disease comes close to posing.

Research has since revealed multiple risk factors contributing to this heightened vulnerability. People with schizophrenia have impaired thermoregulation due to various factors, including challenges in managing dopamine, a neurotransmitter associated with temperature regulation. Additionally, they often exhibit an imbalance between the sympathetic and parasympathetic nervous systems, which can worsen psychotic episodes and increase the risk of adverse cardiovascular events during extreme heat.

Lastly, antipsychotic medications used to treat schizophrenia can further impair sweating, exacerbating their ability to dissipate heat.