The Health Impacts of Extreme Heat

CW: Psychiatric Disabilities, Pregnancy, & Death

As the summer began, an important email arrived in the inboxes of a small group of health-care employees north of Boston. It cautioned that local temperatures would reach the 80s.

By some standards, an 80-degree day is not scorching. Even in Boston, the temperature was not high enough to warrant an official heat advisory for the general public.

However, research has shown that those temperatures, coming so early in June, will most likely increase the number of heat-related hospital visits and deaths in the Boston area.

The targeted email notice received that day by the doctors and nurses at Cambridge Health Alliance in Somerville, Massachusetts, is part of a pilot initiative sponsored by the organization Climate Central and Harvard University’s Center for Climate, Health, and the Global Environment, known as C-CHANGE.

The messages are being sent to medical providers at 12 community-based clinics in seven states: California, Massachusetts, North Carolina, Oregon, Pennsylvania, Texas, and Wisconsin.

The first email alert of the season was sent out to each location when local temperatures reached the 90th percentile for that community. That happened on May 14 in a Portland, Oregon suburb amid a spring heat wave. This happened in Houston in early June.

When estimates suggested that the thermometer would hit the 95th percentile, a second email alert was sent out. Rebecca Rogers, a primary care physician at Cambridge Health Alliance, received her second notice on July 6, when the temperature reached 87 degrees.

The emails encourage Rogers and other professionals to pay special attention to patients who are particularly vulnerable to heat. This includes outdoor workers, the elderly and patients with heart disease, diabetes, or renal disease.

Youth athletes and others who cannot afford air conditioning or do not have stable housing are also at risk. Heat has also been associated with difficulties during pregnancy including premature birth, stillbirth, and a low birth weight.

Studies show that disabled people are also vulnerable to heat-related illnesses and fatalities. Some are more likely to have health issues that hinder the body’s ability to respond to heat, while others may experience social isolation, which has been associated with increased heat risks.

One study done by the American Geophysical Union found that during the EHE,(extreme heat event) last year people with schizophrenia were much more at risk of serious illness or death than the general population. Antipsychotic medications such as quetiapine, haloperidol, and risperidone, are commonly prescribed to treat schizophrenia. Antipsychotic medications can also impair thermoregulation.

People with chronic renal disease and ischemic heart disease were also at a higher risk. In addition, those with psychological disabilities are more likely to die during heatwaves due to issues controlling their body temperature, as well as stigma and social marginalization, which may limit their access to support networks.

All community members’ safety and well-being should be a priority. If an emergency plan is developed without everyone in mind, millions of lives are at risk.


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Bebinger, Martha. “When Temps Rise, so Do Medical Risks. Should Doctors and Nurses Talk More about Heat?” KFF Health News, KFF, 1 Sept. 2023,

Konkel Lindsey. ‘Taking the Heat: Potential Fetal Health Effects of Hot Temperatures’. Environmental Health Perspectives, vol. 127, no. 10, Environmental Health Perspectives, p. 102002, https://doi.org10.1289/EHP6221.

Lee, Michael Joseph, et al. ‘Chronic Diseases Associated With Mortality in British Columbia, Canada During the 2021 Western North America Extreme Heat Event’. GeoHealth, vol. 7, no. 3, John Wiley & Sons, Ltd, Mar. 2023, p. e2022GH000729, https://doi.org10.1029/2022GH000729.

Sabe, Michel, et al. ‘Antipsychotics for Negative and Positive Symptoms of Schizophrenia: Dose-Response Meta-Analysis of Randomized Controlled Acute Phase Trials’. Schizophrenia, vol. 7, no. 1, Sept. 2021, p. 43, https://doi.org10.1038/s41537-021-00171-2.

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