The voltages are set automatically. I'm running a memory diagnostic right now and will report the findings and the voltages once it's done. I have not overclocked anything. I've always seemed to have heat issues from just normal use so I've never had any desire to do so. I'm not sure if this makes sense or not but it seems that the longer I have the machine off, the longer it takes to freeze up after I turn it on again.
Just for informational purposes, the original overheating issue was caused by a not great stock heatsink and dried up thermal grease.
Edit: the memory diagnostic locked up about 62% through. Here are the voltages:
Also, I didn't install the cooler myself, I had it installed at a local shop. Is it possible that the person didn't reattach the psu connections properly? I just find it very suspect that I was able to play a resource heavy game for so long and the issue didn't arise until after I had quit it.