ROCKVILLE, Md. — Home generators could be put to use as hot temperatures and summer storms stress the power grid. Aside from the usual warnings about carbon monoxide poisoning from generators used indoors or in garages or carports, homeowners are also being cautioned about how the generators are hooked up.

For some who go out and buy a generator, “someone tells them you can plug that right into your dryer outlet” to power the home, said Pete Pedersen, manager of emergency preparedness for Pepco.

That setup could be dangerous or even deadly.

During an outage, an improperly hooked-up generator can send electricity out into a neighborhood’s electrical equipment.

“A home generator can ‘backfeed’ a system and have enough voltage out there to injure or kill somebody,” Pederson said.

The generator power could be sent back into de-energized power lines and could also make its way to a transformer, which in turn would put out thousands of volts of electricity.

Pedersen said a proper generator setup involves an electrician installing a manual transfer switch.

“Your power goes out, you go flip that switch,” he said, separating a home from the power grid and allowing it to safely run on generator power.

Additionally, he said when the power comes back on, “our energy’s not going to burn up your generator.”