South Brunswick, NJ — Generators. They’re the savior of many a suburban home, especially in the aftermath of storms such as Isaias, when hundreds of thousands of New Jersey residents are still without power as of Wednesday.

But generators can be extremely dangerous and even lethal: They will release carbon monoxide into a home if they are not used correctly and placed well away from a residence.

In South Brunswick Tuesday night, police responded to “at least three calls about generators,” said South Brunswick Deputy Chief Jim Ryan. In the most serious incident, a 61-year-old woman and her 9-year-old granddaughter had to be hospitalized for carbon monoxide poisoning.

The home’s generator was located right by the back door and the toxic fumes were coming back in through an open window, said police. The generator had been running for eight hours prior to the woman calling 911.

Police were called to the Robin Road home at 10:55 p.m. Tuesday. The woman, at home with her granddaughter, said she had difficulty breathing and felt very fatigued, said rescuers. She had an existing heart condition and thought she was having a heart attack; in fact, that’s what she told the 911 operator when she called.

“The officer got to the home in three minutes and as soon as he got there, he heard the noise of the running generator,” said Ryan. “It was right outside the home. It had been placed by the back door, but it was right under an open window, so the exhaust was coming back into the home. The fumes were still pouring into the house.”

South Brunswick police officers Matthew Hagood, Tyler Harpster and Sergeant Nathan Labuda responded. Police immediately evacuated the woman and child from the home and called the fire department.

“When my crew got there, the levels of carbon monoxide were 350 parts per million, and the generator had been running for approximately eight hours,” said Kendall Park Fire Chief Chris Perez. “350 is a lethal amount of carbon monoxide. You will start to feel disoriented and sick right away. The problem is most people think they are just tired. It will kill you.”

“If the officer had waited inside there, he would have been overcome himself,” said Ryan. “The fact that he heard the generator running made him think, ‘Something is off here.'”

The woman and her granddaughter were sick enough that they both had to be hospitalized overnight Tuesday for carbon monoxide poisoning, said Ryan. Their condition is unknown as of Wednesday.

Just hours earlier, Perez and his team of firefighters responded to a home on Blue Jay Court in South Brunswick, for the carbon monoxide detector going off.

“That call was at 5 p.m. When we got there, the carbon monoxide was around 70 parts per million,” said Perez. “They had been running their generator in the garage. The homeowners said, ‘Oh, we didn’t know that (it was supposed to be outside).”

Improper use of generators is a huge problem, said the fire chief. Suburban homeowners often purchase them, as a back-up when storms knock out electricity, but:

“Make sure the generator is at least ten to fifteen feet away from your home, in a well-ventilated space and not running in an enclosed area of any kind,” said Perez. “A lot of people think they can put it right outside their back door or a window, but it needs to be ten to fifteen feet away.”

Carbon monoxide is a clear, odorless gas. Residents usually have no idea they have been inhaling it until they feel extremely ill.