Computing and server power supplies are typically sized larger to deliver the maximum power the system may need. However since systems are not often used to capacity a smaller power supply may be used in conjunction with a thermal sensor to monitor a critical component of the power supply defined as the particular component within the power supply whose temperature reaches its maximum allowed limit sooner than any other power supply component when the average (continuous) power may exceed the power supply's max rating. When a critical temperature has been reached, an interrupt signal is generated by the power supply to signal the host to throttle back until the temperature comes back into an acceptable range.