This is based on several user complaints which have since resulted in several postings on Apple’s support forums, in which users are complaining that the Touch ID button has become too hot to touch. We’re not talking about a button that feels warm, but rather a button that has been described as “burning hot” or “extremely hot”.
It becomes so hot to the point where they are unable to touch it without harming themselves in the process. It seems to be some kind of overheating issue which was something we reported on earlier where phones are shutting off at 50% battery, and in some cases won’t even turn back on or won’t even charge.
Apple has yet to respond to these complaints, but one Apple support rep claims that they had not heard about this issue prior to this. In any case hopefully Apple gets it sorted out, but if you are planning on getting a new iPhone 6s or 6s Plus, maybe you should wait for some of the later production models where the issues might already be resolved.