Heat and flickering mean the cord is dying.

Yes, those are the two main signs. Heat at the plug or connector means there’s resistance where there shouldn’t be — usually a loose or corroded connection inside. That heat can melt insulation, start a fire, or just get worse until the cord stops working entirely.

Intermittent power (lights flickering, tools cutting out) usually means the internal wire has a break or is shorting. Often happens at the point where the cord bends most — right where it enters the plug or the device. You’ll jiggle it and it works for a second, then dies.

Both are “replace now” signals. Extension cords are not worth diagnosing or repairing — the labor alone costs more than a new one. A good 12-gauge cord is like $20. A fire is a lot more.

Don’t wait for the cord to get hot to the touch. If it’s warm, toss it.