Voltage is what effects heat. You won't see much of a different in temps between 4.5 and 4.7ghz at the same voltage. The relation is that 4.7 might require more voltage for stability. If you want to take it a step further, try decreasing the voltage and run prime95 for hours to see if it will crash. For right now I imagine you are fine. If you have any random restarts, drop your frequency.
Edit: a lot of people don't consider an overclock stable until it can run prime95 for 24hours straight. I myself just run it overnight.