Plugging extension cords into each other is a bad idea.

No. Do not cascade extension cords. It’s unsafe.

Plugging one extension cord into another — called daisy-chaining — increases resistance and voltage drop. That makes the cords run hotter than they’re designed for, which can melt insulation or start a fire. The longer the combined length, the worse it gets.

You’re also adding extra connection points where things can pull apart, short, or spark. And you’re probably creating a tripping hazard the length of a football field.

If you need more reach, buy a single extension cord rated for the distance and the load. That’s it. Not two cheap cords end-to-end.

This is not where you try to save fifteen bucks.