A matched population-based case-control study was conducted on exertional heat illness (EHI) in male Marine Corps recruits in basic training at Parris Island, SC. Physical fitness and anthropometric measurements were obtained for 391 of 528 cases of EHI identified in this population during 1988-1992, and 1467 of 1725 controls matched to cases by initial training platoon. The risk for developing EHI increased with increase in body mass index (BMI = weight·height-2) as measured on arrival and with increase in time to complete a 1.5-mile run conducted during the first week. Recruits at highest risk for developing exertional heat illness had a BMI of 22 or more kg·m-2 and a 1.5-mile run-time of 12 or more minutes. These recruits had an eightfold higher risk for developing exertional heat illness during basic training when compared with those with BMI less than 22 kg·m-2 and 1.5-mile run-time under 10 min (P < 10-6). Only one-fifth (18%) of male recruits met these criteria for high risk, but they accounted for nearly half (47%) of the exertional heat illness cases occurring during the 12-wk basic training course.
Uniformed Services University of the Health Sciences, Bethesda, MD
Submitted for publication June 1995.
Accepted for publication March 1996.
The authors would like to acknowledge Paul Popernack, Kathryn Stewart, and Andrew Sellers for assistance in data management, and personnel at the U.S. Marine Corps Recruit Depot, Parris Island, SC and the Naval Hospital, Beaufort, SC for assistance in data collection.
This work was conducted with collaboration from Howard University Hospital, Washington, DC (Dr. Kark); the Walter Reed Army Institute of Research (Dr. Kark); Naval Hospital, Beaufort, SC (Dr. Gastaldo); and the U.S. Army Research Institute of Environmental Medicine, Natick, MA (Dr. Wenger).
This work was supported by grants from the Uniformed Services University of the Health Sciences (RO87CI) and from the U.S. Army Research Institute of Environmental Medicine (GY87CV), as well as staff and administrative support from all of the above institutions.
The use of Navy medical records in the preparation of this material is acknowledged, but it is not to be construed as implying official Department of the Navy approval of the conclusions presented. The views expressed in this paper are those of the individual authors and do not necessarily reflect the views or policy of the United States Department of Defense.
Address for correspondence: Dr. John W. Gardner, Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814-4799.