Ward E-9 heat index vs design envelope LIVE TRACE / 24H / 06.18.31 Hourly heat index rises above the safe envelope after midnight A red line climbs from 33.4 degrees at zero hour to a peak of 47.8 degrees at twenty three hundred, crossing above the cyan safe envelope after eighteen hundred. 50°C 46°C 42°C 38°C 34°C 47.8°C PEAK LOAD / 23:00 CYAN: DESIGN ENVELOPE 00:00 06:00 12:00 18:00 24:00