2007, Piran, Slovenia

Environmental Ergonomics XII
Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007
RESULTS
As time progressed, core temperatures deviated significantly among trials (P0.05), nor significant time by uniform interactions (P>0.05).
Table 1: Averages for the last 5 min of each trial, or from the last sampling period. Data are
means (standard errors of the means), with probabilities (one-way analysis of variance).
Variable Control Torso armour Armour + helmet ANOVA
Core temperature (°C) 37.8 (0.08) 38.0 (0.07) 38.3 (0.12) P=0.015
Skin temperature (°C) 36.5 (0.18) 37.1 (0.19)
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37.4 (0.25) P=0.010
Heart rate (b.min -1 ) 114.6 (4.2) 120.6 (2.7) 131.9 (4.7) P=0.006
Body mass change (kg) 1.32 (0.57) 1.72 (0.16) 1.74 (0.17) P=0.043
Perceived exertion (6-20) 10.3 (0.33) 11.2 (0.40) 11.5 (0.58) P=0.180
Thermal sensation (1-13) 10.2 (0.43) 10.3 (0.30) 10.7 (0.32) P=0.564
Thermal discomfort (1-5) 3.0 (0.38) 3.1 (0.33) 3.3 (0.33) P=0.784
Vigilance (correct) 86.44 (0.87) 85.67 (0.93) 85.22 (1.01) P=0.652
Reasoning (correct) 7.33 (0.24) 7.11 (0.31) 7.22 (0.22) P=0.833
Filtering (correct) 81.00 (0.60) 79.78 (1.01) 80.44 (0.88) P=0.598
Working memory
(correct)
53.33 (0.97) 53.44 (0.90) 53.33 (1.18) P=0.996
Divided attention
(correct)
37.78 (0.52) 38.33 (0.76) 37.56 (0.41) P=0.631
Reaction time (correct) 38.67 (0.47) 38.11 (0.51) 38.22 (0.64) P=0.751
DISCUSSION
The principal aim of this project was to evaluate the physiological strain, and the risk of
exertional heat illness, when military personnel are required to wear combat body armour
during very-light to light workloads in environments typical of the northern Australian
summer. When the complete combat armour state was adopted, the projected time to 39.5°C
was reduced from 7 h to