Throttling involves changing the cycles that the chip acts on, to simulate a speed of 2.8 ghz. It would be a nice trick on your chip, but may not be what you want to do when overheating.
Hope that sounds funny. Your chip was built before throttling was invented, so it's not an option.
The lord there is very right. Your chip should idle around 37c, and run full load @ 50 to 55c max.
Start by giving everything inside the case a good cleaning. Dry compressed air works well. If the compressor in you garage doesn't have a drier, you can use a vacuum on blow, if you are careful, or buy some cans of air.