Shot my 5D in near 100 degree whether on the pavement on a drag strip a couple of weeks ago, and never had a warning. It wasn't continuous shooting but I have never experience and issue with overheating on mine.

So possibly this indicates an increased problem with the 7D compared to the 5D

Well I've said it twice before, but I suspect the dual processors in the 7D as opposed to just one in the 5D Mk. II might possibly be the cause of the difference between the two. Just shot two clips indoors at 1280p60; room temperature about 74 deg. F.

The first clip recorded fine; the second showed the temp. warning indicator at less than five minutes in (see attached pic).

Here was my test this morning. Time lapse of the 7D in 78 degree air conditioning at 720 60p.

7D overheat time lapse on Vimeo

As you can see at about 30 minutes the high temp icon kicks in.

I just tried 480p60 indoors, 74 deg. F, got to 25:30 before the temp. warning.

So far I've been unable to record a full 30 minutes at 480p60 without getting the temp. warning.

What about normal 24fps 1080p shooting? This could be a serious problem.

Since when is 24fps "normal," Bill? Heh. Well if you want a test with an oddball frame rate, I just set it up. We'll see what happens.

how did you record so long at that frame rate?

That is a definite possibility. I wonder, however, if the DIGIC is the source of the heat or if the sensor itself is the problem. I have noticed that the 5D stays cooler with an external display since the LCD and backlight can be turned off. The strings in the firmware for the 5D refer to EFIC(?) sensor temp, not DIGIC temp.

Another thought that occurs to me is that Canon has lowered the temperature at which the warning comes on. A beta tester of the 1.1.0 firmware on a movie set reported (on another forum) that they were using two 5D bodies to be able to swap them out when they got hot. Both bodies eventually developed stuck/hot pixels as a result of continuous multi-hour shooting days. Perhaps Canon wants to be more careful that the 7D bodies don't develop this problem?

yep I know someone who used 3 5dmkII on a film set and all of them are now dead due to overheating. A worry. Hence the cautious warning on the 7d. You should all move to England. It's cold here.

Maybe somebody requested that the 7D behave more like a RED ONE, so the Canon engineers added an overheating feature. ;) ;) ;)

Okay, so I shot several back-to-back clips at 1080p30 (this morning) and 1080p24 (just now), indoors in an air-conditioned room at around 74 deg. F. *without* getting the temp. warning indicator.

However, as posted earlier, under the same conditions I couldn't get a single 480p60 clip to record a full 30 minutes before encountering it. At 720p60 it happened four minutes into the second clip.

So my guess at this point is that the 60p frame rates will produce the temperature warning sooner than shooting at 24p or 30p. In my opinion 1080p24 is the frame rate which is the least taxing on the camera. I'll bet it works hardest, and therefore heats up more quickly, at 480p60 because of all the real-time down-conversion it has to do. Knocking it down to 640x480 from eighteen megapixels is probably a bigger job than going to 1920x1080 or 1280x720. But I'm just guessing.

I use the 5d2 as a supplemental cam for the past few months and have never shot a clip longer than 4 mins - and while I do feel that the body warms up, I've never seen a temp warning. I can see if you were running this thing full out, that the body would continue to heat up and possibly cook.

If this real a serious threat - wouldn't we have seen more cooked 5d2 bodies by now?

I couldn't find any warning in the 5d manual (though I may have missed it). Maybe this is an ulterior motive behind the 12 minute recording limit?

How about outside with no air conditioning? I can't always shoot in comfortable conditions.

I just read the warning on the manual, it said holding a hot camera for a long time could slightly burn your hand, I wonder how hot it would get for them to put a warning in like this, and maybe this is the reason why they recommend using UDMA card to avoid banding and noise?