The heat is on: Causes of hospitalization due to heat waves identified

In the largest and most comprehensive study of heat-related illness to date, Harvard School of Public Health (HSPH) researchers have identified a handful of potentially serious disorders—including fluid and electrolyte disorders, renal failure, urinary tract infections, sepsis, and heat stroke—that put older Americans at significantly increased risk of winding up in the hospital during periods of extreme heat.

The study also showed that risks were larger when the heat wave periods were longer and more extreme and were largest on the heat wave day, but remained elevated for up to five subsequent days.

“An innovative aspect of this work is that, rather than preselect a few individual diseases to examine, we considered all possible causes of hospital admission during heat waves in order to characterize the effects of heat on multiple organ systems,” said Francesca Dominici, professor of biostatistics at HSPH and senior author of the study.

The study appears online December 23, 2014 in the Journal of the American Medical Association (JAMA).

Although it’s well-known that heat waves pose a health risk to older people, previous studies had investigated only a small number of potential heat-related health outcomes, such as cardiovascular and respiratory diseases.