Skin Wetting Helps Cool Older Adults in Very Hot, Dry Weather

Long Beach, Calif. (April 5, 2024)—Spraying the skin with water helps reduce core and skin temperature in older adults during extremely hot and dry weather, according to a study at the University of Texas Southwestern Medical Center. In addition, skin wetting lowered the heart and sweat rates of study participants. Researchers will present their work this week at the American Physiology Summit, the flagship annual meeting of the American Physiological Society (APS), in Long Beach, California.

“Our early results suggest that wetting the skin with a water spray may help older adults deal with extreme heat.”—Zachary McKenna, PhD

The research team investigated whether using a water spray to wet the skin could help prevent heat strain in older adults during extreme heat. Older adults are prone to heat injury such as heat exhaustion and heat stroke, according to the Centers for Disease Control and Prevention. They are more susceptible to heat injury because their bodies cannot adjust to sudden temperature changes as fast as younger people.

Ten older adults ages 67–84 spent three hours in a hot room that recreated the conditions of the 2018 Los Angeles heatwave. The simulated temperature was 116 degrees Fahrenheit with a 15% relative humidity. Study participants visited the room on two occasions: once in which their skin was sprayed with water and the other with no skin wetting. During their visits, participants mimicked daily activities with short sessions of light cycling. Researchers measured their core and skin temperature, heart rate, sweat rate and skin blood flow to compare the effects of skin wetting versus not wetting the skin. They found that wetting the skin with a water spray reduced core temperature by 0.59 degrees Fahrenheit and heart rate by six beats per minute.

The goal of this study was to give older adults another tool to stay healthy during extreme heat. “This easy and low-cost strategy may help protect older adults from overheating and experiencing related health issues during heatwaves,” said Zachary McKenna, PhD, lead author of the study and a postdoctoral research fellow at the Institute for Exercise and Environmental Medicine in Dallas.

NOTE TO JOURNALISTS: The American Physiology Summit will be held April 4–7, 2024, in Long Beach, California. To request the full abstract, “Skin wetting attenuates the thermal strain of older adults exposed to very hot and dry heat with accompanying activities of daily living” (#868), or schedule an interview with the researchers, conference organizers or presenters, contact APS Media Relations or call 301.634.7314. Find more highlights from the meeting in our Summit Newsroom.

Physiology is a broad area of scientific inquiry that focuses on how molecules, cells, tissues and organs function in health and disease. The American Physiological Society connects a global, multidisciplinary community of more than 10,000 biomedical scientists and educators as part of its mission to advance scientific discovery, understand life and improve health. The Society drives collaboration and spotlights scientific discoveries through its 16 scholarly journals and programming that support researchers and educators in their work.