I would like to see a Canon R5 test done in hot conditions.  Maybe it's not the CPU that Canon is trying to protect. I live in southern California and shoot in the desert a lot. I've had problems with my 5Ds when shooting Milky Way images when nighttime temperatures are over 90F.  I have to be careful not to use live view too much or wait to shoot so that the camera can cool down. Otherwise with my 5D Mark II  I would get a lot of color noise at ISO 1600.  Especially in the lower right of the frame.  On my 5D Mark IV I get wierd artifacts that look almost like light leaks.