You have to decide. Warm oil flows better and the concept is that because it comes rushing out faster than it takes with it more of the impurity's.So are we supposed to change the oil when the Bronco is totally cold? I was under the impression that it was best to run it a little then let it cool down for 10 or 15 minutes before change.
Doing it cold means you've given the engine lots of time for all the oil to work its way back down to the oil pan so you'll get more of it, although it will flow slower.
For me personally, I've pretty much always done it cold. Go out in the garage in the morning and do my oil changes.