Exertional Heat Illness Complications and Prognosis Among Service Members.

OBJECTIVE

The aim of this study was to examine exertional heat illness (EHI) complications and their associations with post-EHI outcomes.

METHODS

In a retrospective cohort of 24,121 service members (SM) with first-time EHI in 2012 to 2022, we analyzed six EHI complications: rhabdomyolysis, acute kidney injury (AKI), neurological symptoms, acidosis, respiratory/cardiovascular distress, and other organ damage. Post-EHI outcomes included medical military separation and chronic diseases.

RESULTS

Using clustering, SMs were placed into six clusters based on patterns of complications: mild (81%; no complications), AKI/no rhabdomyolysis (5%), rhabdomyolysis/no AKI (6%), rhabdomyolysis/AKI (5%), and neurological symptoms (2%). AKI and/or rhabdomyolysis clusters were associated with being male, being obese, no chronic conditions, reduced medical separation risk, and increased AKI risk; the smaller neurological cluster had more females, chronic conditions, and separation risk.

CONCLUSION

EHI clusters have differential associations with both pre-EHI demographics/history and post-EHI outcomes.