PoE++ can get warm but you wont be doing that with fibre!
Before specifying fibre everywhere I suggest you note that a CAT 6 cable can manage 10G and PoE++. Its a lot more resilient to breakage too, especially outside the data centre.
If you really want to blow some cash there is CAT6A, which is probably not indicated unless you want cable lengths of more than say 50m.
No, the transceivers get hot. This is because of plenty of small metal surfaces, so even if they do not consume too much they will immediately get warm to the touch.
Before specifying fibre everywhere I suggest you note that a CAT 6 cable can manage 10G and PoE++. Its a lot more resilient to breakage too, especially outside the data centre.
If you really want to blow some cash there is CAT6A, which is probably not indicated unless you want cable lengths of more than say 50m.