Yes, higher frequencies and higher voltages= more heat. I would reload factory defaults and use the guide I linked to above to gradually OC your system. With your cooler, I would start with a multiplier of 42 or 43 and first try changing the offset sign to "-" and then type in .005. Exit Saving changes and boot into windows to check your voltage under full load. If it doesn't boot, change the sign to "+" and again, use .005. Hopefully, that will get you an offset voltage of about 1.2-1.25. If it runs that for 30minutes to an hour, you can go back in the BIOS and bump the multiplier up to the next notch(43 or 44)........rinse, repeat.
Overclocking is a process and sometimes you have to start all over to get to where you want to be. Reference my screenshots and the guide beforehand to familiarize yourself with the options, and what they do. I am going to put a guide at the end of this post that will give you more information about the options in an Asus Motherboard's BIOS. We'll get you there, it just takes time.
Kelly Asus Z77 Tuning Guide.zip