A family of five was hospitalized with carbon monoxide poisoning in Portland, Oregon, on Sunday, according to local reports.
Investigators said the poisoning was the result of the family's use of a generator and cooking with propane inside an apartment.
"Someone called 911 because a child approximately 8 years old was found lying in the snow outside," Lt. Terry Foster, a fire inspector for Portland Fire & Rescue, told Fox News Digital on Tuesday.
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"When crews arrived, they did a search of the apartment and found four people lying on the floor of the apartment and began removing them. They were all transported by American Medical Response."
The investigators found high volumes of carbon monoxide in the apartment, where a generator and camp stove were being used, Foster said.
"These devices were what led to this emergency."
The occupants were conscious when transported, but were exhibiting symptoms consistent with carbon monoxide poisoning, Foster said.
The adjacent apartments were checked and evacuated.
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"Crews were able to ventilate the structure and residents were able to move back in quickly," Foster noted.
A severe winter storm hit Portland on Saturday, leaving thousands of people without power.
The apartment complex had not had access to heat since a tree fell on a powerline across the street the previous day.
"DO NOT use generators indoors because carbon monoxide is a silent, colorless, odorless, tasteless killer," Portland Fire & Rescue advised in a post on X (formerly Twitter).
Isabela Royer, a woman who lives across the hall from the family that was poisoned, called 911 after one of the family members knocked on her door, she told a local news outlet.
"He’s right there and he says, 'Help me, please,'" Royer said.
"I walk out into the hallway, and I look down the stairs at the bay window seating area and his child is throwing up, heaving, obviously sick."
"I dragged the kid outside to get some fresh air and some other guy from their family pulled up and started pulling the rest of the people out of the house," Royer continued.
"The door to their apartment was open and I saw the generator and I knew right away," she added.
Foster said he reached out to the investigator on Tuesday, who reported that they had no further information about the patients.
The lieutenant also reminded residents that if they're unable to warm themselves safely, Multnomah County offers warming shelters throughout the county.
"You can call 2-1-1 to help get you there," he said.
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The most dangerous outcomes of carbon monoxide poisoning can include death, permanent organ damage and long-term neurological effects, according to Dr. Dung Trinh, a brain health expert and owner of The Healthy Brain Clinic in Long Beach, California.
"Carbon monoxide is a toxic gas that can bind to hemoglobin in the blood, reducing its ability to carry oxygen, leading to tissue hypoxia and damage to vital organs," he previously told Fox News Digital.
The effects of carbon monoxide poisoning can vary depending on the severity of the exposure and individual factors.
Those at highest risk include infants, elderly individuals, pregnant women and those with pre-existing respiratory or cardiac conditions, Trinh said.
Each year, carbon monoxide poisoning claims at least 420 lives, according to the Centers for Disease Control and Prevention (CDC).
