Citation

Welles AP, Buller MJ, Margolis L, Economos D, Hoyt RW, Richter MW. Mil. Med. 2013; 178(10): 1141-1148.

Affiliation

Biophysics and Biomedical Modeling Division, U.S. Army Research Institute of Environmental Medicine, 44 Kansas Street, Building 42, Natick, MA 01760.

Copyright

(Copyright © 2013, Association of Military Surgeons of the United States)

DOI

10.7205/MILMED-D-12-00538

PMID

24083930

Abstract

The physiological burden created by heat strain and physical exercise, also called thermal-work strain, was quantified for 10 male Marines (age 21.9 ± 2.3 years, height 180.3 ± 5.2 cm, and weight 85.2 ± 10.8 kg) during three dismounted missions in Helmand Province, Afghanistan. Heart rate (HR) and core body temperature (Tcore) were recorded every 15 seconds (Equivital EQ-01; Hidalgo, Cambridge, United Kingdom) during periods of light, moderate, and heavy work and used to estimate metabolic rate. Meteorological measures, clothing characteristics, anthropometrics, and estimated metabolic rates were used to predict Tcore for the same missions during March (spring) and July (summer) conditions. Thermal-work strain was quantified from HR and Tcore values using the Physiological Strain Index (PSI) developed by Moran et al. July PSI and Tcore values were predicted and not observed due to lack of access to in-theater warfighters at that time. Our methods quantify and compare the predicted and observed thermal-work strain resulting from environment and worn or carried equipment and illustrate that a small increase in ambient temperature and solar load might result in increased thermal-work strain.

Language: en