Accession Number : ADA294495

Title :   Cool Vests Worn Under Firefighting Ensemble Increase Tolerance to Heat.

Descriptive Note : Rept. for Feb-Sep 93,

Corporate Author : NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA

Personal Author(s) : Hagan, R. D. ; Huey, K. A. ; Bennett, B. L.

PDF Url : ADA294495

Report Date : JUN 1994

Pagination or Media Count : 20

Abstract : Firefighting in the Navy firefighting ensemble (FFE) prevents heat dissipation while exposure to high temperatures leads to progressive heat gain. Previous studies in air up to 35 deg C show that cool vests worn under FFE reduce heat strain. However, the effectiveness of cool vests on heat strain during exposure to hot/humid air is unknown. The purpose of this study was to compare a small 4- pack vest (cVs) and a large 4-pack vest (cVl) in minimizing heat strain in men dressed in the Navy FFE, while resting and exercising in hot/humid air (480C/1180F, 50% rh) - Eight males attempted to complete as many cycles as possible of 30 min rest and 30 min walking during three trials (no vest, CVs, and cVl). Measurements included rectal and four skin temperatures, and heart rate. Tolerance time for CVs (58.2i15.8 min) and CVL (60.1 + or - 10.4 min) were longer (p<.05) than NV (49.9 + or - 6.2 min). During the first exercise period, rate of heat storage was greater (p<.05) for NV (111.7 + or - 29.3 W.m2) compared to CVs (96.2 + or - 17.9 W.m2) and CVL (96.7 + or - 20.5 W.m2). Our findings indicate that cool vests worn under the firefighting ensemble attenuate rate of heat storage and prolong heat exposure tolerance time in a hot/humid environment.

Descriptors :   *PERFORMANCE(HUMAN), *HIGH TEMPERATURE, *FIRE FIGHTING, *HIGH HUMIDITY, *FIRE PROTECTIVE CLOTHING, *VESTS, *HEAT TOLERANCE, TEMPERATURE, EXPOSURE(GENERAL), AIR, NAVY, RATES, COOLING, TIME, GAIN, TOLERANCE, MALES, STORAGE, HEAT, HEART RATE, HOT REGIONS, HEAT LOSS, SKIN(GENERAL), RECTUM.

Subject Categories : Stress Physiology
      Thermodynamics
      Protective Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE