The EOS R5 is a recently-released, near-US$4000 Canon full-frame mirrorless camera that can shoot 8K RAW - but for only about 20 minutes straight. This, according to the OEM, is due to the need to protect its processor from overheating. However, a teardown documented on Baidu has found that this same silicon may have been underserved in the way of thermal protection.
https://www.notebookcheck.net/Canon-EOS-R5-a-new-teardown-video-calls-the-nature-of-its-recording-time-limitations-into-question.486505.0.html