STOCKTON — A small electronic monitor about the size of a toaster caught fire Wednesday afternoon at St. Joseph’s Medical Center, but a hospital clerk quickly responded to put the flames out before there was any serious damage.

Fire Department units responded as a precaution and helped vent smoke out a back nonpublic door of the hospital at 1800 N. California St.

No injuries were reported and there was no impact on patients, St. Joseph’s spokeswoman Natalie Pettis said.

The monitor was not being used at the time its battery started smoking and small flames became visible. It was in an empty room in the hospital’s radiology unit. A nearby clerk smelled the smoke, found where it was coming from and extinguished the flames. Other equipment in the room was checked before going back into service, Pettis said.