iPhone 5 infinite restart after opening Camera app

I have an iPhone 5 with iOS 10.3.3. Since a couple of days, my phone crashes and restarts all the time I try to use Camera app (just to make simple photos...). I open Camera app, and the phone just reboots and restarts. As soon as I want to unlock it with my password, it just crashes and restarts again. This endless reboot spiral goes on and on till I start to charge the phone or connect it to a power bank (even though the battery is fully charged).

I've already done a factory reset of my phone, but it still reboots anytime I open Camera app.

Any idea anyone?