burning a dvd with idvd should I watch the temperatures

I would try to avoid prolonged overheating. To help avoid overheating I would make sure to try to consistently burn where you good ventilation and a clear path to the vented ports in the back. Keep your fan blown out according to amount of use. Do a tear down in case you notice overheating using something like Temperature Monitor and replace the thermal paste. The vents around the heat sink can become blocked and cause severe overheating.

http://www.bresink.com/osx/TemperatureMo...

A cooling pad would also help serve your needs, here are some: http://www.google.com/search?client=safa...