Heat Policy Revision for Georgia High School Football Practices Based on Data-Driven Research

Context: Interscholastic heat policies for football have not been evidence based. Therefore, their effectiveness in mitigating exertional heat illness has not been assessed. Objective: To discuss the development of the Georgia High School Association heat policy and assess the effectiveness of revised guidelines. Design: Descriptive epidemiology study. Setting: Georgia high schools. Patients or Other Participants: Interscholastic football players in grades 9 through 12. Main Outcome Measure(s): Heat syncope and heat exhaustion (HS/HE) illness rates (IRs) were calculated per 1000 athlete-exposures (AEs), and relative risk (RR) was calculated as a ratio of postpolicy (POST) IR divided by prepolicy (PRE) IR. Results: A total of 214 HS/HE cases (172 PRE, 42 POST) and 341 348 AEs (178230 PRE, 163 118 POST) were identified. During the first 5 days of the PRE period, approximately 50% of HS/HE illnesses occurred; HS/HE IRs doubled when practice sessions increased from 2 to 2.5 hours and tripled for practices >= 3 hours. The HS/HE IRs in the PRE period increased from 0.44/1000 AEs for wet-bulb globe temperatures (WBGTs) of <82 degrees F (<27.8 degrees C) to >2.0/1000 AEs for WBGTs from 87 degrees F (30.6 degrees C) to 89.9 degrees F (32.2 degrees C). The RRs comparing PRE and POST policy periods were 0.29 for WBGTs of <82.0 degrees F (<27.80 degrees C), 0.65 for WBGTs from 82.0 degrees F (27.8 degrees C) to 86.9 degrees F (30.5 degrees C), and 0.23 for WBGTs from 87.0 degrees F (30.6 degrees C) to 89.9 degrees F (32.2 degrees C). No HS/HE illnesses occurred in the POST period for WBGTs at >90 degrees F (>32.3 degrees C). Conclusions: Results from the PRE period guided the Georgia High School Association to revise its heat and humidity policy to include a mandated 5-day acclimatization period when no practices may exceed 2 hours and the use of WBGT-based activity-modification categories. The new policy reduced HS/HE IRs by 35% to 100%, depending on the WBGT category. Our results may be generalizable to other states with hot and humid climates similar to that of Georgia.