Here we have our first teardown of the Canon EOS R5, and it will give you some idea in how Canon has chosen to control heat. There are a few design choices that I find interesting.
The thermal pads on the CPU don’t cover the full CPU
Aluminum was used instead of copper, though there is added cost and complexity of working with copper.
There is definitely no venting for heat to escape
Is there an issue with the CFExpress slot being so close to the processor?
As pointed out by EOSHD, why does not of this matter when recording externally? I and others think it’s probably some kind of software limit.