Observed Warming Trends at U.S. Army Basic Combat Training Installations and Implications for Future Recruit...

Area of Science:

• Environmental Science
• Occupational Health
• Climate Science

Background:

• Army recruits are highly susceptible to exertional heat illness.
• Rising global temperatures exacerbate heat stress risks during military training.
• Wet bulb globe temperature (WBGT) is a key indicator of heat stress.

Purpose of the Study:

• To analyze WBGT index trends at U.S. Army Basic Combat Training (BCT) installations.
• To quantify the magnitude of these WBGT trends.
• To discuss the potential impacts of increasing temperatures on recruit heat illness and training.

Main Methods:

• Utilized weather data from the early 1960s, including WBGT index measurements.
• Classified high WBGT days considering prior heat exposure to identify recruit risk periods.
• Analyzed WBGT trends quantitatively during warm seasons and full years, comparing decades and BCT classes.

Main Results:

• WBGT index has increased at all four analyzed BCT installations since 1960.
• Ft Jackson, SC, showed the most rapid increase (0.272°C/decade), while Ft Moore, GA, had the least (0.190°C/decade).
• Recruits at Ft Moore, GA, face the highest heat burden, potentially experiencing ~200 hours of hazardous heat during mid-June BCT.

Conclusions:

• Steady increases in WBGT index highlight a growing heat stress risk for Army recruits.
• Adaptations to the BCT program are necessary to maintain training standards safely.
• This analysis provides data to inform medical, training, and policy changes for BCT in a warming climate.