As microprocessors continue to advance in complexity and operating rate, the heat generated in microprocessors during operation increases and the demands on cooling systems for microprocessors also escalate. A particular problem is presented by so-called “hotspots” at which circuit elements at a localized zone on the microprocessor die raise the temperature in the zone above the average temperature on the die. Thus it may not be sufficient to keep the average temperature of the die below a target level, as excessive heating at hotspots may result in localized device malfunctions even while the overall cooling target is met.