How to use Heat Index:
| Apparent Temperature | Heat Stress Risk with Physical Activity and/or Prolonged Exposure |
| 80° to 90° | Exercise caution; dehydration likely if athlete fails to drink adequate fluids |
|
91° to 103° |
Exercise extreme caution: Heat cramps or heat exhaustion possible |
|
104° to 124° |
Danger: Exertional heat cramps or heat exhaustion likely, heatstroke possible |
|
125° and up |
Extreme Danger: Exertional Heatstroke highly likely |