Ummm...about 350 volts dangerous.
If they get near the power supply (which if you look from the back is where the fan is), that needs to be unplugged and left off for a day before you can even touch inside.
The processor big square thing on the board inside...that gets quite hot. If I have to replace one, I normally have to let it cool a good hour or two AFTER turning it off. The reason it has a fan built on top of it to keep a constant cooling temperature. If not for that, the processor gets so hot it could melt everything.
Be safe, keep the cover on when there's kitties present!