Heat Tolerance and Exertional Heat Illness in Female Military Recruits

摘要

We studied healthy recruits (controls), and recruits with exertional heat illness(EHI) during basic training. We copied pertinent clinical and training records on all identified EHI cases during this reporting period, numbering approximately 100 cases-fewer than usual but the 1997 hot season was cooler than usual until mid-August. Unlike past years, when most EHI cases occurred during the first 4 weeks of training, and while running, 40% of EHI cases occurred during a 52-h exercise, the Crucible in file 11th (next-to-last) week of training. The Crucible, new this year, involved no significant running, but includes two 9-mile marches with pack, with no more than 4 hours sleep a night. In 20 healthy recruits, we measured core temperature (T-core) with swallowed telemetering sensors from 0500 to 1700 hours each day of one Crucible, and collected 7 blood samples at 12-h intervals, starting the day before. In 80 other recruits in four cohorts, we measured T-core during middle-distance (2.5 to 4 mile) runs at three stages of training, and the final march of the Crucible. We also obtained blood samples on enrollment and initial, final, and recovery sample with each event, for selected clinical measurements and assessments of immune/inflammatory function.