Field Assessment of Wet Bulb Globe Temperature - Present and Future

Existing doctrinal guidance for preventing heat injury in military settings is based on measurements of the Wet Bult Globe Temperature WGBT index.. An existing military WGBT measurement device NSN 6665-00-159-2218 was employed by a U.S. Army Reserve unit during field training exercises at Fort Bliss, TX in 1986, Tinker AFB, OK in 1987, and Fort Hood, TX in 1988. The majority of heat casualties seen in these three exercises 31 out of 35 occurred when the daily maximum WBGT index exceeded 85 F. Experiences of this unit suggest that a strictly enforced, WBGT-based, heat injury prevention program was effective in minimizing both the number and severity of heat injury prevention program was effective in minimizing both the number and severity of heat-related injuries. During the exercises at Fort Hood in 1988, a preliminary evaluation of methods to obtain WGBT information from polar orbiting weather satellites was conducted. Data from 11 satellite passes were obtained and the average error, or bias, of the satellite-derived WGBT values was found to be -1. 8 F too low with a variation standard deviation of or - 3.7 F around that bias. Work is in progress to improve this future heat stress assessment technology. Heat stress, WGBT index, Heat injury prevention, RA III.