To get back to the original question:
I have only fried one stick of ram from voltage, and I have run at 3.5volts!! In a water cooled system with cpu temps under 40c, case under 25c and mobo under 30c.
The one I fried was only at 3 volts, but my temps were NOT as good: cpu was under 40c but case was 30c and mobo was 34c.
One important consideration is airflow over the ram: this seems to be more effective than heat spreaders in fact.
Position a fan blowing directly onto the ram slots and you should be ok.
But here is an even better piece of advice: if you can't afford to wreck the ram, don't do it!
Running out of spec IS inherently dangerous and far more likely to break something.