Physiological Effects of Chemical Protective Garments During Exercise and Heat Stress.
Abstract
The present study was designed to examine the effect of protective garments, with a range of insulation and permeability characteristics, on changes in physiological parameters during exercise and on heat balance in warm and hot environments. Dressed in the U.S. Army Battle Dress Uniform (BDU), the U.S. Army Chemical Defense Ensemble (CDE), a butyl rubber Toxic Agent Protective (TAP) suit, and the CDE covered by a two-piece vinyl rainsuit (RAIN) volunteers walked on a treadmill at a workrate of 481 + 35.4 watts. Environmental conditions for hot experiments were 38/26/43 degrees Celsius, Tdb/Twb/Tbg, and for warm trials, 29/24/34 degrees Celsius. The subjects exercised until reaching 39 degrees Celsius Tre, max HR, or volitional fatigue. Pre- and post-experiment nude and clothed weights were measured and used to calculate sweat production (SP) and sweat loss (SL). TAP and RAIN had significantly shorter tolerance times than the CDE or BDU in both warm and hot environments. For the same suit, tolerance time was reduced in the hot environment compared to warm conditions. Sweat production was significantly increased as suits became less permeable and as the temperature increased from warm to hot. Sweat evaporation (SE) was affected significantly only by the ensemble. Body heat storage occurred at a lower rate than predicted, especially in the hot environments where Tdb was greater and Tsk which should make radiative heat loss negligible and in trials where individuals wore impermeable ensembles (TAP and RAIN) which should have blocked evaporative heat loss.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1998
- Accession Number
- ADA336598
Entities
People
- Stefan H. Constable
- Susan H. Bomalaski
Organizations
- Armstrong Laboratory