Abnormal heating of the device isn't very specific, but then again if you haven't installed any new programs on the device its hard to tell if the device was overheating due to excessive CPU load or because there's an excessive influx of power going straight through the device.

I am not sure on the latter part (i.e. the excessive influx of power), I'm presuming the battery management entity (BME) should pick such issues up and may not allow excessive currents to charge the device.

I'm also thinking at this point it might be a good idea to check the output of dmesg and to maybe also enable R&D mode to see if there's a way to bypass this issue or at least to ascertain what could have been the culprit.