Embodiments of the invention relate to energy efficient and conserving thermal throttling of electronic device processors using a zero voltage processor state. For example, a processor die may include a power control unit (PCU), and an execution unit having power gates and a thermal sensor. The PCU is attached to the thermal sensor to determine if a temperature of the execution unit has increased to greater than an upper threshold, such as while the execution unit is processing data in an active processor power state. The PCU is also attached to the power gates so that upon such detection, it can change the active processor power state to a zero processor power state to reduce the temperature of the execution unit. When the sensor detects that the temperature has decreased to less than a lower threshold, the PCU can change the processor power state back to the active state.