We sit in our trucks for hours on end filling out reports and powering all the accessories.
We get many miles out of our engines with no concerns. I will say that since Fuel injection the engines seem to be easier on oil when idling.
In our Toyota's the water temp stays within 5 degrees no matter what I'm doing. 4x4, sitting, responding or driving around.
They seem to have a pretty good control on the temps.
When we had Fords the temps were all over the place. But the last model year we had them was 1999-2001. Never had a Dodge even though we had them.
Now with all that said, the most I idle my own vehicles is a max of a couple of minutes. I just don't want the by products getting in my oil.
Take care, Bill