Underclocking Intel CoreDuo

Is there any way to underclock a 2.0Ghz Intel CoreDuo processor inside the Macbook? My gf's 1.83Ghz puts out a lot less heat and I would totally be willing to have a slower processor for less heat. At least 1.83Ghz. Any help would be appreciated.

tbh i dont know about overclocking or under clocking on a mac i would like to know how to overclock my mac but also i see ya point for underclocking my best advice is stick it in low power mode this might help.

With the Macbooks you can make it work for better battery life which I assume makes everything work more power efficient and slower. The setting should be under Energy Saver in the System Preferences Panel.
Bryan