As @hydro311 mentioned, your current rule has a few issues.
I recommend thinking about this one from a different perspective. Take a look at the following rule, which is much simpler to me. 
Hope this helps!
This rule uses a "Periodic Schedule" trigger, using the Every 30 Minutes feature. It also has a Required Expression that will prevent the Actions from being run every 30 minutes unless the temperature is greater than 85 degrees. The actions are pretty simple: 1) turn on the fan 2) turn off the fan after a 5 minute delay.
