Update:
We did the ride - 106 degrees with humidity rising head index to 115. We made it 30 miles and then all suffered heat exhaustion. We called our SAG wagon (our friends mini-van and another's truck) and they picked us up. We felt proud/exhausted. The ride was hilly (outrageously so in my opinion) giant hills that flat spotted out in between (and the ride was supposedly planned by an expert) and hot.
I took water and gatorade and was hauling my LHT (very comfortable long-distance, btw) up hills with a ridiculous amount of weight. It was murder, god-awful murder. But we all want to do it again in less heat. I felt proud I did a thirty miler - really pushed myself in that weather. I didn't give in until I almost dropped. Stupid? Perhaps. But am I proud I did my best? Absolutely.
(Btw, what is Heed? I've never heard of it.)