Of these 2 I would take Acer because of a SSD and 8GB RAM.
CPU is basically same but HP's one has little bit better integrated GPU.
I am sure that some expert here from AU will find something even better for you.
Probably cooler is not on it nicely or they forgot thermal paste?
I don't know really, if you have guarantee, RMA it !!
Don't use it anymore man, it will damage!
Totally overheating!
Clean your laptop and use it on flat surface (wood, like table), never used it on lap or blanket, in bed because it cannot properly cool itself!!!