Schizophrenia heat wave death risk was roughly three times higher during British Columbia’s 2021 heat dome than in comparable periods, making it the strongest association among 26 chronic medical conditions examined in a provincial analysis. The result is a warning about a specific eight-day disaster, not a universal ranking of every illness in every hot spell.
Researchers compared the medical histories of 1,614 people who died during the June 2021 event with 6,524 people who died on the same calendar dates in the preceding nine years. Temperatures exceeded 40°C for days, and more than 600 people died from the heat in British Columbia, according to Science.
People with a history of schizophrenia had about a 200% increase in mortality relative to typical summers, the reporting said. By comparison, mortality was 18% higher for people with coronary artery disease and 36% higher for people with kidney disease during the event. Those comparisons describe associations in population records. They do not establish that schizophrenia alone caused an individual death.
What did the British Columbia heat-wave study find?
More than 8% of all people who died during the hot week had a history of schizophrenia, compared with 2.7% of deaths on matching dates in typical years. Of 280 deaths the provincial coroner certified as heat-related, 37 involved people with schizophrenia, more than 13% of that group, Science reported.
The study’s scope matters. It tested conditions in British Columbia’s exceptional 2021 heat dome, rather than proving that schizophrenia exceeds every other medical condition in every heat wave or forecasting any one person’s risk.
Why can heat be especially dangerous for people with schizophrenia?
The danger appears to come from several systems failing together. Experts cited by Wired said schizophrenia can be linked to altered thermoregulation, the body’s process for shedding heat through functions including sweating and blood-vessel control. Some antipsychotic medicines can also have anticholinergic effects, including reduced sweating and increased heart rate, which may make cooling harder.
Heat can also worsen anxiety, disrupted sleep, and psychosis symptoms. People may have trouble recognizing that they are overheating or acting on the warning. Co-occurring illness, social isolation, homelessness, and housing without effective cooling can compound the physiological risk, according to Science and Wired. Medication effects are potential risks to discuss with a clinician, not a reason to change treatment without medical supervision.
Why do ordinary heat alerts fail?
Generic alerts assume people receive, trust, and can act on them. In interviews with 35 people with schizophrenia who survived the heat dome, participants described avoiding news or official warnings because of paranoia or distress, and some said cooling centers felt unsafe or unwelcoming because of stigma, The Conversation reported. Others lacked air-conditioned homes or were unhoused.
Researchers and advocates cited in the reporting have called for heat plans before an event, check-ins by caregivers or support workers, confirmation of access to air conditioning or a cooling center, and public warnings that explicitly identify schizophrenia as a high-risk condition. That is less glamorous than another generic “drink water” alert, but it addresses the access failures the heat dome exposed.
This story draws on original reporting from WIRED.
