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Risk conditions experienced by individuals at a different range of heat indices
| Heat index | Risk conditions by prolonged physical activity |
|---|---|
| < 27 °C | Comfortable |
| 27–32 °C | Fatigue |
| 32–41 °C | Muscle cramps, sunstroke, heat cramps |
| 41–54 °C | Sunstroke, muscle cramps, exhaustion, heatstroke |
| < 54 °C | Sunstroke/heatstroke |
