Using the camera does use alot of resource on the phone @Yardie but it should only shut down if the phone then has a pop up saying the phone is over heating.
Hopefully this is a glitch that won't resurface.
You could clear the phone's System Cache Files anyway.
Clear your phone's System Cache Files by turning your phone Off and then from a set series of button presses go into the phone's System Files and clear the cache. No information is lost this way. You may need to insert your headphones or hook upto a computer with your data cable to get to this menu on the phone. https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/
Current Phone > Samsung Z Fold³ 5G.
@Yardie: Further to he advice offered above, I'd also recommend checking the Google Play Store for any updates for the Zoom app that might address this issue. If you continue to experience overheating problems, please follow the link below for some additional troubleshooting steps.