My laptop charger over heated once, can this be dangerous?

Yes ofcourse. :( when you sit in the bed you need under computer put restraints or a board. And you need clean ventilator too. Be sure ventilator is full of dust. You need to unscrew the open place where the ventilator and take away dusts... I am a girl and i can do this you can do this too ;) But if you don't clean your computer will heats and something can burn from ;( Because if computer once stopped work, than it will be twice too.... Good luck ;)