I have a variable power source(5V, 6V, 9V, 12V, etc...) with a usb plug which I had powering my pi 3B a few months ago, but one day (a few months ago) I accidently had the power source set on 6V(it might have been 6.5V, I forget). The pi was running normally, but I noticed it was running extra hot. Probably about twenty minutes later, I noticed my mistake, immediately shut the pi down and set the power source back to 5V. Since then, the pi has worked perfectly(as far as I can tell), without any noticeable problems. My question is,
1.) Would this have reduced the longevity and lifespan of my pi?, and
2.) What overvoltage protection parts(if any) does the pi have? Does it have an onboard voltage regulator/monitor?