Don't daisy-chain extension cords.

Just don’t. The multiple outlets at the end exist so you can plug a few things into one cord, not so you can plug another cord into it.

Every extension cord has a maximum amp rating. When you plug one cord into another, you’re drawing that combined load through the first cord’s plug and wire. The second cord adds distance, which increases resistance and voltage drop, and the first cord’s breaker (if it has one) can’t protect the second cord. Overheating, fire, and tripped breakers are the results.

There’s no safe “limit” for daisy-chaining because the practice itself is unsafe. If you need more length, buy a single cord that’s long enough and rated for the load. If you need more outlets, use a power strip with a built-in circuit breaker — but never plug that into an extension cord either. Same problem.

The short answer: one extension cord, one power strip, each plugged directly into a wall outlet. That’s it.