Heat intolerance, heat exhaustion monitored: a case report
Armstrong, L.E.; Hubbard, R.W.; Szlyk, P.C.; Sils, I.V.; Kraemer, W.J.
Aviation Space and Environmental Medicine 59(3): 262-266
1988
ISSN/ISBN: 0095-6562 PMID: 3355482 Document Number: 315436
A 32-year-old male (Mr. A.), monitored during an 8-d heat acclimation (HA) investigation, unexpectedly exhibited heat intolerance and heat exhaustion. Thirteen other males completed HA without indications of either heat intolerance or heat exhaustion. Because Mr. A. responded normally to HA on days 1-4, the intervention of an unknown host factor on days 5-8 was suggested. Mr. A.'s heat exhaustion episode (day 8) was apparently forewarned by loss of body weight and increased .DELTA.HR, .DELTA.Tsk (days 5-8) and .DELTA.Tre (days 7-8) during daily 90-min trials. His symptoms indicated classical salt depletion heat exhaustion, but the calculated salt deficit (< 0.1 g NaCl .cntdot. kg-1 body weight) was mild. Post-heat exhaustion serum enzyme levels were either normal (ALT, AST) or acutely elevated (CPK). Blood beta-endorphin and cortisol levels were six times and two times greater than control values, respectively. This case report is unique because clinical/physiological measurements and blood analyses were performed before, during, and after heat intolerance and heat exhaustion.