Even though overclocked, the real culprit when it comes to all the "DANGER WILL ROBINSON" warnings is temperature. As long as the CPU is maintaining a temp COMFORTABLY (usually no more than EightyºC) below the spec referred to as "T-Junction" (usually 100ºC) you should be okay. A simple water cooler like the CORSAIR Hydro Series H80 can keep your temperatures down to reasonable levels without going nuts with extreme H20 cooling systems with all their piping and fussy installation nightmares. It also helps to have a good guide to all your BIOS overclocking settings, as well as to know how to adjust voltages and memory timings to keep things operating as they should.
My system is an Intel I7-950 that I built in 2009. It's been running reliably overclocked from its native 3.07GHz to 4.2GHz all that time. That's about a 27% overclock, and as far as I think I should push it. Core temps don't redline. My flight simulator apps are the only programs I have that actually push the limits. A lot of games like we play here, rely heavily on the GPU rather than the CPU. I've upgraded my video card twice since the build in 2009. The system still screams! I'm deliriously happy with it. I have had one HD failure, though. Luckily it was my backup drive, so I didn't loose much except the backups. I'm now packing about 5.15TB total storage (2x2TB, 1x1TB, 1x150GB WD VelociRaptor.)
Again, as long as the voltages, memory timings, temperatures are set and monitored properly, there should be no real danger to your expensive processor chip or memory modules. Get it wrong, though, and one of 2 things will happen. 1) The chip's onboard protection circuits will shut it down before operating in T-Junction long enough to cause real damage, or 2) The Magic Smoke will be released. It's the smoke that makes all this stuff run. Release the Magic Smoke into the atmosphere, and it shall never run no more.
.