Table 1.

Description of sports- and recreation-related heat illness data collected by two national injury surveillance systems

System	Reporting institutions	Population	Heat illness definition	Data collected
NEISS-AIP(3)	66 nationally representative U.S. hospital EDs	Entire U.S. population	Nonfatal ED visits with a reference to heat illness (e.g., “heat exhaustion”, “dehydration”, etc.) in the narrative description, occurring during a sport or recreational activity	Demographics, brief narrative, consumer product information
High School RIO™ (4)	100 nationally representative U.S. high schools	High school athletes	Dehydration or heat exhaustion/stroke during a practice or competition, assessed by a medical professional, and resulted in ≥1 days of time loss from athletic activity	Exposure, demographics, illness characteristics, event characteristics