Don't even think about camping, it will stay hotter than the hinges on the gates of Hell all night. Like the others said, leave even before the dawn and avoid the worst of the heat. I do know people that went on a group tour in June from San Diego to Denver, during the dry heat season, and they'd leave the motels at 3AM on the Blythe-Wickenburg leg.

The humid monsoon season usually has started in the Sonoran Desert by early July, so you may also encounter humidity, clouds, and some showers. Though it knocks the high temperatures down somewhat, it's even more uncomfortable.

The worst heat I've encountered was 110 F, but it was dry heat...once riding north out of Redding in Northern California in August, and once on Labor Day along the coast from San Clemente. Both areas have lots of shady spots and water--on the Redding trip I brought a heavy cotton long sleeved tee shirt, and would soak it and put it over my jersey, and. while riding, pour water from my bottles onto the sleeves for cooling. On the Labor Day heat blast, I used the cold outdoor showers at the public beaches to completely soak myself and get my core temp down. In both cases, five minutes of riding and I'd be completely dry again. And it went down to 60 F the first night out of Redding at Castle Crags SP (2000'), so I could sleep well.

None of my above tactics will do much good in the desert...why exactly are you going to do this torture instead of a much more pleasant tour? If you want a challenge, I'd suggest some really mountainous trip.