You asked
Does the camera overheat when recording 4k?
Here is what the site says about that.
From Video: For filmmaking: - A body with full-width 4K (no heavy crop), 10-bit recording, and a headphone jack. - Fast primes or constant-aperture zooms, so exposure doesn't change as you zoom. - ND filters, because to keep the shutter at about twice the frame rate (1/50s at 25 frames a second) in daylight with a wide aperture, you need to cut light.
From Video: What matters: - Stabilisation. In-body stabilisation plus an electronic mode makes handheld and walking footage usable. For smooth movement, a gimbal still does better. - Recording limits and overheating. Some small bodies stop recording after a while in 4K, especially in the heat. If you film long talks, events or interviews, check real-world reports on how long a camera records before it stops. - 10-bit and log profiles. These give you room ...
Quoted from this site's pages.