The possibility is small, but with voltages and frequencies under software control, yes. AFAIK even ordinary "non-overclocker" hardware has this capability, despite not being exposed in the BIOS settings, for power management purposes.

This is especially problematic with certain laptops --- I remember hearing about some that would overheat when booted into BIOS or even an alternative OS for an extended period of time, since they depended entirely on a driver to turn on and control the CPU fan...