SAF-102a EXPANDED HEAT INDEX CHART
Paul Smith, K5PRS
02 AUG 2025
As provided by ChatGPT:
Expanded Heat Stress Risk Matrix
(Includes Temperature, Humidity, and Exposure Time)
| Heat Index (°F) | Humidity % | Short (<1 hr) | Moderate (1–3 hrs) | Long (>3 hrs) |
|---|---|---|---|---|
| 80–89 | 30–60% | Low risk | Low to moderate risk | Moderate risk |
| 61–90% | Moderate risk | Moderate risk | Moderate to high | |
| 90–99 | 30–60% | Moderate risk | Moderate to high | High risk |
| 61–90% | High risk | High risk | Very high risk | |
| 100–109 | 30–60% | High risk | Very high risk | Extreme risk |
| 61–90% | Very high risk | Extreme risk | Medical emergency likely | |
| 110–129 | Any humidity | Very high risk | Extreme risk | Severe medical risk (even with short exposure) |
| 130+ | Any humidity | Extreme risk | Life-threatening | Do not remain exposed — risk of death |