Yes, even it is 40C+ here in the desert, the running doesn't stop !!! I just get out earlier and drink more !!! I stop running only if the temperature reaches 50C.
1. cut time or distance by 10%-15%
2. drink plenty of liquid, before and after running
3. don't be afraid to stop and rest or drink during a run
4. run as early as possible or as late as possible to avoid heat or sun
5. don't run fast, or train as if this is one month before a race, just bank the mileage, run as much as possible within the physical condition rather then staying at home; by the time October comes, you will find out the hard work in summer does pay off!!!