Table 1 Wet-bulb globe temperature (WBGT) levels for modification or cancelation of workouts or competition for healthy adults [15]
From: Preventing heat illness in the anticipated hot climate of the Tokyo 2020 Summer Olympic Games
WBGT | Continuous activity and competition | Training and non-continuous activity | ||
|---|---|---|---|---|
°F | °C | Non-acclimatized, unfit, high-risk individualsa | Acclimatized, fit, low-risk individualsa,b | |
≤ 50.0 | ≤ 10.0 | Generally safe; EHS can occur associated with individual factors | Normal activity | Normal activity |
50.1–65.0 | 10.1–18.3 | Generally safe; EHS can occur | Normal activity | Normal activity |
65.1–72.0 | 18.4–22.2 | Risk of EHS and heat illness begins to rise; high-risk individuals should be monitored or not compete | Increase the rest: work ratio. Monitor fluid intake. | Normal activity |
72.1–78.0 | 22.3–25.6 | Risk for all competitors is increased | Increase the rest: work ratio; decrease total duration of activity. | Normal activity monitor fluid intake. |
78.1–82.0 | 25.7–27.8 | Risk for unfit, non-acclimatized individuals is high | Increase the rest to work ratio; decrease intensity and total duration of activity. | Normal activity monitor fluid intake. |
82.1–86.0 | 27.9–30.0 | Cancel level for EHS risk | Increase the rest to work ratio to 1:1, decrease intensity and total duration of activity. Limit intense exercise. Watch at-risk individuals carefully. | Plan intense or prolonged exercise with discretionc, watch at-risk individuals carefully |
86.1–90.0 | 30.1–32.2 | Cancel or stop practice and competition. | Limit intense exercisec and total daily exposure to heat and humidity; watch for early signs and symptoms | |
≥90.1 | ≥32.3 | Cancel exercise. | Cancel exercise uncompensable heat stressd exists for all athletesc | |