Application of a Computer Model to Set Heat Strain Threshold Limit Values: Evaluation During a Simulated Army Basic Combat Fitness Test
Abstract
The risk of exertional heat illness during military activities can be reduced by setting Threshold Limit Values (TLVs) using Wet Bulb Globe Temperature (WBGT) index. A study was undertaken to investigate if computer predictions of heat strain were accurate enough to set TLVs for military activities. Physiological strain during a simulated Army Basic Combat Fitness Test (treadmill walking at 6.8 km/h, 0%! incline) in a warm environment (WBGT 24.3 deg C) was assessed in 20 apparently healthy male soldiers with no history of heat illness. Measured environmental variables, metabolic heat production, subject anthropometry, and estimated clothing thermal and evaporative resistances, were entered into a rational heat strain model. The range in measured rectal temperature (T(sub re)) at the end of exercise was 37.7 to 39.3 deg C T(sub re) was correlated with exercise oxygen uptake (rho = 0.68, P < 0.001). Differences between predicted and measured T(sub re) after 60 minutes and at the end of the simulated Army Basic Combat Fitness Test, or point of subject withdrawal, were + 0.18 (1 SD = 0.37) and + 0.03 (0.48 deg C respectively. It was concluded that computer predictions of heat strain have potential value for setting valid TLVs for military activities.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2002
- Accession Number
- ADP012450
Entities
People
- A. S. Weller
- E. M. Kellett
- M. Bentley
- W. R. Withey