you a point regarding temps is right,no offence
a 100-300mhz oc will not affect temp that much. but i bet you oc to 600mhz or more temps will be high @stock cooler
It depends of course on what you consider to be "high". I set the voltage to be fixed at 1.1V for my i5 760, then OCed it to 3.4 GHz (turbo still enabled). With the stock cooler, it would peak at 70ish C at 100% load - and ~65 for typical real-world workloads. That is not ridiculously high, and will not fry the CPU (it would peak to ~55 C at stock clock speed on the stock cooler). The key in my particular case was not allowing the mobo (a Gigabyte board) to automatically overvolt the CPU in accordance with my OC settings - that blew the temps to the moon. My i5 760 OCs to 3.4 GHz with no overvolting whatsoever, and it consequently doesn't get all that hot.