ESP8266 Community Forum

I accidentally applied reverse voltage to my ESP8266-1 for a period of time and not unsurprisingly, it is now broken. However, after I realized what I had done, I'd thought maybe I'd "gotten away with it" so continued so applied normal voltage to try some tests. Nope ... it was dead. So I grabbed it with fingers to pull it from the board and let go quickly with a whoop ... it felt like it was red hot. After it cooled down, I plugged it back in and again applied 3.3V (normal) and the chip started heating almost instantly.

So ... being a hobbyist and relatively new to electronics, if one "kills" an IC by applying reverse voltage ... and hence all bets are off, is it "unheard off" for now applying normal power (to this broken IC) for it to reach extremely high temperatures?

nope, its a dead bug.
in general most chippies will act as a diode, apply reverse voltage and all the ESD protection diodes on each pin will turn on, this can protect the core to some extent but with enough current (and in chip form .. a lot of current is 50mA) some of these will short out.
You now have probably a healthy chip with low value resistors that used to be diodes connected to each pin to ground and rail.