A warm extension cord means something is wrong.

No.

Even a low-wattage device shouldn’t make your extension cord feel warm. If it does, you’ve got a bad connection, damaged wire, or too-thin gauge — none of which are normal or safe.

Extension cords get warm when resistance is high. That could be from internal fraying, a loose plug, or a cord that’s simply too small for the load (even if the load seems low — think about voltage drop over distance). A 50-foot 18-gauge cord running a lamp is fine. A 50-foot 18-gauge cord running a space heater is not, but a warm cord at low wattage means the cord itself is the problem.

Don’t ignore it. Resistance generates heat, and heat starts fires. Toss the cord and get a properly sized one. A few bucks now beats a house fire later.

Unplug it and don’t use it again.