Essentially, an increase in operating temp due to overclocking, while being handled by the extra efficient coolers and fans overclockers use, is STILL an increase in internal operating temp.
There is a heat-exchanging interface designed onto (Not Into) the CPU that aids in the transfer of heat, BUT the heat still exists in the CPU until transferred. That transfer is NOT instantaneous!
A lot depends on the degree of cooling penetration, and I have never heard that any cooler actually can claim to completely cool the 'heart' of a CPU.