Mirrorless cameras can be more prone to overheating, but it’s not true that all mirrorless cameras overheat badly. The main reason is that a mirrorless camera keeps its sensor and processing circuitry active for live view, EVF, and video, which generates heat. In a DSLR, the sensor is not working continuously during optical viewfinder shooting, so heat load can be lower in that use case.

Body size matters too: smaller, lighter cameras have less room and mass to absorb and dissipate heat, so compact mirrorless models may hit thermal limits sooner, especially in 4K video or other high-data-rate modes. That’s why some cameras limit frame rates or recording modes to manage temperature.

So this is partly a general mirrorless design challenge, especially for video and prolonged live-view use, but overheating behavior is still very model-dependent. Some cameras handle heat better than others depending on their internal design, recording modes, and thermal management.