i’ll disagree with all of this. we are shooting a doc now on a 5d mk2’s and a 7d, we have done many many long sit down interviews without over heating. all you have to do is watch your clip times, when the talent gets a sip of water start and stop a new clip.
It does take some clever workarounds but it’s not as tough as it sounds. we have shot for as long as 6 hours with one lunch break to let the cameras cool, neither even showed signs of over heating and this is indoors but with out any ac running