Before revision:  Since the power consumption and reliability of microprocessors are highly dependent on temperature, both designers and, later on, run-time temperature management units must be able rely upon accurate heating and cooling modelsto handle heat generation and peak temperature. If exponential cooling models are justified for actively-cooled microprocessors, e.g., by forced air or water cooling, for passively cooled processors however, as frequently found in embedded systemssuch as mobile phones, an exponential law may not be theoretically justified .
After revision:  Since the power consumption and reliability of microprocessors are highly dependent on temperature, management units need accurate thermal models. Exponential cooling models are justified for actively-cooled microprocessors, e.g., by forced air or water cooling, for passively cooled processors however, as frequently found in embedded systemssuch as mobile phones, an exponential law may not be theoretically justified .