Why is it when you print something out or copy something, the paper comes out really hot!?

Some printers actually use a heating device to "fuse" the toner onto the paper. Certain parts inside your printer can get as hot as an iron. It's the same with a photocopier too. Be very careful. Hope this helps!

The fuser, which makes the letters, pictures, etc, cling to the paper is very hot (it melts the plastic toner into the paper) and is the last part of the printer that the paper is run through.

The laser printer causes the paper to become electrostatically charged so that the toner powder sticks to it, it then runs the paper through a hot roller to melt the toner onto the paper.

Machines generate heat. Laser printers and photocopiers also need a heater to help transfer the ink.

I'm assuming you are printing with a laser printer. The printer uses heat to fuse the toner to the paper. It gets very hot, so that is why the paper is hot.

Because the paper just ran through a machine that is hot.

Most printers use a 'fuser roller' or something like it, to dry and set the ink they lay on your paper. The heat from that will warm the paper temporarily.

Some InkJet and Laser printers uses heat to fuse the image onto the paper, that's why. It depends on the type of printer you are using. Almost all copiers use the same process. The image is rolled onto the ink roller then pressed against the paper then heat is used to burn the image onto the paper. Hope this clears it up.