Effects of Exercise-Heat Stress While Wearing Five Toxic Agent Protective Systems
ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA
Pagination or Media Count:
This study evaluated heat strain in four developmental toxic agent protective systems relative to the standard Toxic Agent Protective TAP suit during exercise-heat stress. Eight subjects 6M,2F completed five experiments in a 38 deg C, 30 rh climate, wearing 1 Self Contained Toxic Agent Protective Outfit STEPO with rebreather STEPO-R 2 STEPO with tether STEPO-T 3 Improved Toxicological Agent Protective ITAP suit with Self-Contained Breathing Apparatus ITAP-SCBA 4 ITAP with blower ITAP-B and 5 TAP. Experiments were treadmill walking at 0.89 m.sec-1, 0 grade, exerciserest cycles of 2010 min, for 240 min in STEPO and 120 min in ITAP. Mean metabolic rates were 1 STEPO-R, 298-26 W 2 STEPO-T, 299-34 W 3 ITAP-SCBA, 275-26 W 4 ITAP-B, 255-27 W and 5 TAP, 222-40 W. In STEPO, subjects received whole body cooling at STEPO-R, 200-36 W and STEPO-T, 186-59 W. In ITAP, subjects received shirt only cooling at ITAP-SCBA 17234 W and ITAP-B, 178-41 W. TAP had no cooling. Comparisons were not made between STEPO and ITAP systems. Exposure time was longer p0.03 in STEPO-R 83-22 min and STEPO-T 106-39 min than in TAP 46-10 nun. Exposure time was longer p0.05 in ITAP-SCBA 85-20 min and ITAP-B 87-25 min than in TAP46-10 min. Rate of heat storage S was less p0.05 in STEPO-R 37-8 W.m-2 and STEPO-T 38-12 W.m-2 than in TAP 77-15 W.m-2. S was less p0.05 in ITAP-SCBA 51-16 W.m-2 than in TAP 77-15 W.m-2. Microclimate cooling significantly reduced S in three of four systems and increased exposure time in all four systems relative to TAP.
- Medicine and Medical Research
- Stress Physiology
- Protective Equipment