I am actually a bit surprised that I ran into it as I've rattled off some long bursts with birds. But, probably not something that was 2 pics per second for 18 minutes. I do wonder if converting all those images to CRAW maybe takes a bit of additional computational power?

As for the camera, no warning, no issues and I did not notice anything until the very end. The camera continued to perform perfectly even a few minutes after I did my measurements as my wife was giving our dog a bath as I was testing this and I rattled off a bunch more pics of that. I just felt my grip get a little bit warm. The 87F was behind the LCD panel, which is what I've heard others say is where it gets warmest.

I do not shoot like this very often. Even birds on a perch will be a burst and then waiting. Maybe some long time lapses? But, it can happen taking pictures, not just video. I do wonder if it was the CRAW conversion, whatever goes into that. As 2 images per second of RAW is ~100 MB/sec even for 18 minutues and it seems like video modes have no issue with that bit rate. Instead it seems like they have an issue once getting into the >~800 Mb/sec range.