Cincinnati, OH – As weather in the Tri-State took its first dip to near freezing temperatures over the weekend, Cincinnati crews responded to their first home emergency involving carbon monoxide (CO).

Shortly after midnight Monday, firefighters and medical technicians responded to the scene of possible CO poisoning.

A woman coming home to her apartment complex in the 2000 block of Stratford Avenue said she heard her downstairs neighbor calling out for help.

The woman called 911. When crews arrived they found two semi-conscious adults and a dog. A high level of the poisonous gas that is a byproduct of burning fossil fuels such as natural gas was immediately detected in the apartment.

Firefighters said the occupants turned on the heat three hours earlier and a clogged flu pipe prevented proper ventilating of the heater.

Duke Energy workers arrived on the scene and turned the gas lines off to the building.

The adults were transported to the University of Cincinnati Medical Center for treatment. The dog was take by the SPCA until the owners were well enough to take it back.

Emergency responders said had the neighbor not come home when she did, the outcome of the incident might have been much worse.

The incident stands as a reminder for anyone with gas heat in their home to take extra precautions as they turn on furnaces for the first time.

Carbon monoxide is an odorless, colorless gas usually given a faint odor by energy providers like Duke Energy for easier detection. If you turn on your heater and there is an odd smell in your home, turn the unit off.

The Center for Disease Control recommends having gas heating, water heaters and other gas, oil or coal burning appliances serviced by a qualified technician every year.

Also, install a battery-operated or battery back-up CO detector, and make sure to change the battery every time you change clocks in the fall and spring. If the alarm goes off, the CDC says leave your home immediately and call 911.

Immediately seek medical attention if you feel dizzy, light-headed or nauseous and suspect CO poisoning.

Things not to do include using a generator or other gasoline or charcoal-burning device inside your home, basement, garage or near a window. Don’t run a vehicle inside an attached garage, even with the door open.Don’t burn anything in a stove or fireplace that isn’t properly vented. And finally, don’t heat your house with a gas stove.