Table 1

Event and EHS subject characteristics

Event
(date)
WBGT (°C)Air temperature (°C)Relative humidity (%)Age (year)Height (m)Weight (kg)*APFT
2-mile run time (min:s)
ECTemp at point of collapse (°C)Casualty rectal Tcr (°C)†Pre-event
risk factors
5-mile run
17 July 2018
21.5±1.223.2±0.384.9±8.2301.7585.713:3039.241.10
7-mile ruck
7 August 2018
19.5±1.421.8±0.775.0±5.4221.91102.1¶14:0040.041.30
12-mile ruck
11 March 2019
14.2±0.214.5‡90.5±4.9191.7072.613:4040.141.9
5-mile run
30 April 2019
13.8±0.914.7±0.888.3±4.3331.7577.113:0039.441.70
12-mile ruck
17 July 2019
22.5±0.422.6±0.494.1±2.5271.7888.513:3140.842.20
5-mile run
20 August 2019
26.0‡24.0‡95301.8393.015:0539.242.30
  • *In combination, height and weight show all our EHS cases with a BMI close to or exceeding 25, which in the civilian world would be considered overweight. However, for these military candidates, this BMI is much more reflective of muscle mass versus fat mass and thus, BMI may inaccurately label the demographic overweight.

  • †Rectal temperatures were taken for patients who had EHS prior to casualty evacuation.

  • ‡Estimated using general weather data for Fort Benning, Georgia.

  • §Volunteer reported a recent immunisation.

  • ¶Individual value >2 SD from cohort mean but not a significant outlier according to the generalised ESD test.

  • APFT, Army Physical Fitness Training; BMI, body mass index; ECTemp, estimated core temperature; EHS, exertional heat stroke; ESD, extreme Studentised deviate; Tcr, core body temperature; WBGT, wet bulb globe temperature.