With heat indexes varying from 95 - 111 degrees, running in the middle of the day is Brutal! I have had several out-and-back runs lately (on lunch break) where I've gotten half way out and regretted my timing!
We have to be careful in extreme heat, being sure to hydrate and stretch even more than usual. Sugar drinks become very important (gatorade, powerade, FRS, EFS, etc). Also, remember that you can't simply wait until after the run to recovery hydrate, you can't even wait until the middle of the run, you really need to be drinking and hydrating before you head out on your run in the first place.
Now, the obvious solution to this is run early in the morning or late at night to avoid the heat and the direct sunlight, and I would strongly recommend this to everyone! However, you also have to remember that if you are preparing for a race, you need to prepare for it under race conditions. If you are running a race that will take you through the mid-day heat on asphalt, then running only first thing in the morning on grass isn't going to prepare you for the race ("train how you will compete") and your body will have a huge shock on its hands if race day is the first time you experience those conditions