UC researchers recruit older adults for extreme heat health study

“Seniors are considered especially vulnerable to heat-related illness. Extreme heat is even more dangerous to their health and poses an even greater risk,” said George Leikauf, PhD, center co-director and professor in the Division of Pulmonary, Critical Care and Sleep Medicine within the Department of Internal Medicine.

Leikauf and his team are seeking participants who are 50 or older, live in the Cincinnati area and do not have residential air conditioning.

Researchers will follow participants through the summer, tracking physiologic strain and biomarker signals during periods of heat stress.

Each participant will receive an Oura Ring, valued at about $350, to monitor sleep, step count, activity level, heart rate and skin temperature. Researchers will use the data to measure the body’s physiological response to extreme heat and identify signs of heat-related strain. Participants also will have a heat detector installed in their homes.

In addition, participants will be asked to complete daily health questionnaires and undergo blood draws and nasal swabs before and after any heat waves. They will be compensated for taking part.

Researchers will analyze blood samples collected before and after heat waves using transcriptomics, the study of a complete set of genes expressed in a sample. The process may enable researchers to identify disease biomarkers and measure how environmental conditions affect the body.

“We don’t know yet what the outcomes will be,” said Leikauf.

Older adults face a higher risk of adverse health effects in extreme heat, Leikauf said, including heart attacks, severe respiratory illness, kidney failure, dysphoria from sleep loss and impaired decision-making.

“All the functions of the autonomic nervous system tend to wear out with age,” said Leikauf. “Older adults also experience rising core temperatures that can remain elevated for hours as thermoregulation becomes more difficult. Some medications commonly taken by older adults can also increase their sensitivity to heat, particularly among those with chronic health conditions.”

Prolonged exposure to extreme heat can lead to hyperthermia, a dangerous rise in body temperature that occurs when the body absorbs or produces more heat than it can dissipate. Symptoms can include dizziness, nausea, headache and rapid pulse, and may progress to heat exhaustion or life-threatening heat stroke.

The University of Cincinnati’s Center for Collaboration on Climate & Community for Health conducts innovative, interdisciplinary research on extreme heat and its health impacts while also leading community outreach initiatives. The center was formally announced in the fall of 2024 and is funded through a three-year, $4 million grant from the National Institutes of Health.

Featured image at top: iStock/Miguel Angel Flores.