Table 1

Binary and categorical domains relevant to exertional heat illness (EHI) susceptibility in military personnel

Demographic and situational factors
 Occupational seniorityRecruits*; junior ranks; senior ranks and officers
 Age<30; >30 years
 Prevailing climateHot climate*; temperate climate—summer months*; temperate climate—other months
 Pacing of activityGroup-paced or self-paced
 Clothing ensemble wornOcclusive* (standard uniform +/− additional insulation, such as body armour);vented (reduced insulation relative to standard uniform, with exposure of bare skin below the elbow)
Individual susceptibility factors
 Physical fitness levelPhysically fit§, or unfit*
 Heat acclimatisation statusAcclimatised or unacclimatised*
 Hydration stateDehydrated* or euhydrated/overhydrated
 Medical historyPositive for EHI* or no history of EHI
 Sleep balanceSleep deprived* or rested adequately
 Febrile or infectious (intercurrent) illnessPresent* or absent
  • *Considered at increased risk of EHI by traditional risk stratification.

  • §Indicated by passing military fitness tests within 6 months prior to EHI episode.