Temperature extremes tied to more ER visits for dementia patients

People with dementia were more likely to visit emergency departments after periods of extreme heat or cold, according to preliminary research presented at the European Academy of Neurology Congress 2026. The findings add evidence that severe weather can create short-term health risks for people with neurological disorders as climate change makes temperature extremes more common.

Researchers at the IRCCS Institute of Neurological Sciences of Bologna in Italy analyzed emergency department records from 2015 through 2024 for residents of the municipality of Bologna. The study included 13,680 people with dementia and 2,755 people with Parkinson’s disease.

The team examined whether very hot or very cold temperatures were followed by an increase in emergency department attendance. According to the European Academy of Neurology, extreme heat in the study was about 29.7°C, the 95th percentile of observed temperatures, while extreme cold was about 1.5°C, the 5th percentile.

Dementia patients showed higher risk after heat and cold

Among people with dementia, extreme heat was linked to an 11% rise in emergency department visits within three days of exposure, the researchers reported. The association was measured as a relative risk of 1.11, with a 95% confidence interval of 1.04 to 1.19.

Extreme cold showed a later pattern. The researchers found a 14% increase in risk around 10 days after cold exposure, with a relative risk of 1.14 and a 95% confidence interval of 1.03 to 1.26.

The heat-related association was strongest among people ages 70 to 90. In that group, emergency department attendance rose 19% within three days after extreme heat, according to the study team.

The preliminary analysis did not find clear evidence that extreme temperatures increased emergency department visits among people with Parkinson’s disease. The researchers reported a possible pattern after heat exposure that needs further study, but no clear link with cold.

The team cautioned that the Parkinson’s disease group was smaller, which may have reduced the analysis’s ability to detect an effect. They also said different temperature thresholds may matter for people with Parkinson’s disease.

Researchers cite stress on frail patients

Lead author Dr. Luca Vignatelli said the study showed signs of a “harvesting effect,” in which a rise in emergency visits is followed by a temporary dip. He said that pattern suggests extreme temperatures may bring forward health events that otherwise would have happened later, concentrating demand on health services.

Vignatelli said the differing patterns between dementia and Parkinson’s disease may reflect the distinct disease processes behind the two conditions, even though both are commonly grouped as neurodegenerative diseases.

He said several mechanisms could help explain the dementia findings. One possibility is that heat or cold places physiological stress on frail people; another, still unproven, is that temperature extremes may speed up disease-related biological processes.

Behavior may also play a role, Vignatelli said. People with dementia may be less able to recognize danger or take protective steps during severe weather because of cognitive impairment, while cognitive symptoms are less common and usually appear later in Parkinson’s disease.

Study points to planning needs

The researchers said the findings could guide caregivers, clinicians and local health systems during extreme weather. Vignatelli said local authorities should reduce social isolation and make climate shelters easy to reach during hot and cold periods.

He also said health care professionals should actively support people with cognitive impairment during hot weather, and that telemedicine could help deliver care during both heat and cold.

The work is part of the MANDEA project, which is studying how climate, air pollution, green space and socioeconomic conditions affect people with neurological disorders. The researchers said they hope the project will help health systems prepare for the health effects of climate change.

This story draws on original reporting from Medical Xpress.