Why should you not charge your phone overnight?

A cellphone should not be charged overnight (or for more than five or six hours straight at any time) because of the fire risk from the resulting heat development after running such a device for long periods of time.

RESLINA: you can charge your phone overnight. THERE IS NOTHING WRONG WITH THAT!! Besides, its not even charging for that long! Your home phone is always plugged in, day and night. That's not causing any "heat development", and neither is your cell being charged.