Very irresponsible and poor planning. Whenever I read stories like this, I think about NH's 'negligent hiker law.’
The general consensus is that if it is going to be hotter than 90 degrees in Palm Springs, don't do it. The rocks hold the heat even when he air is cool at night- you can feel the heat coming off of the rocks.
I've done the trail in May before on a day that was 90+ degrees in Palm Springs. We started at 3 am. I'm not a fast hiker, but by 9 am I was regretting the decision. We made it just fine, but I ended up carrying a friends pack (he had bad cramps) for the toughest/hottest parts of the trail... about 2400 ft of climbing in just over 2 miles!
So, when are you coming down south Steve to join in on the fun?