The problem is when you plug one of these (as someone already linked) into the 20 amp socket: https://www.homedepot.com/p/GE-12-ft-2-Wire-16-Gauge-Polarized-In

The problem is when you plug one of these (as someone already linked) into the 20 amp socket: https://www.homedepot.com/p/GE-12-ft-2-Wire-16-Gauge-Polarized-Indoor-Extension-Cord-White-51954/203806535 https://www.homedepot.com/p/GE-12-ft-2-Wire-16-Gauge-Polariz... Everyone in the US has a bunch of these. 16ga is good for 13 amps. Even if everything is working properly, two 10-amp devices will draw 20 amps and the cable will melt before the breaker pops. If everything is not working properly, and there is a short-circuit, the cable will still probably melt before the breaker pops. This is why the OP gets it exactly backwards - she is looking at the big cable/connector and thinking "that's dangerous!" No, danger comes from the weakest link in the system, not the strongest. That weakest link must be a fuse or breaker.