Four women got carbon monoxide poisoning — from a hookah. Now, they're warning others.

When Rachel Micheaux invited her three friends over to her apartment last month for a girls’ night, she never would have predicted that hours later they would end up in the hospital with carbon monoxide (CO) poisoning.

The women were enjoying pizza, cake and some tequila as they danced and played truth or dare. In between snacks and games, they smoked hookah — a water pipe used to inhale flavored tobacco that’s heated with charcoal — over the course of about four hours.

Micheaux, 24, opened the balcony door of her roughly 1,000-square foot apartment, cracked a window open in a separate bedroom and had her air purifier running.

“A lot of people had this idea that we were hot boxing hookah, which is not true,” Micheaux told USA TODAY. “Or they were under the impression that we were just chain smoking back to back for hours, which is also not true.”

About two hours in, Micheaux closed her balcony door because it was getting chilly. Things went downhill from there.

“It was like an instant hangover, like a migraine times 10,” Micheaux said. “It felt as if someone was pounding my head with a hammer.” One of the other women said she didn’t feel right and wanted to lay down. Everyone chalked it up to being tipsy, despite having little to drink.

That’s when the CO alarms in Micheaux’s apartment went off. She has had issues with her fire alarms (which also serve as carbon monoxide detectors) randomly turning on before, so Micheaux turned them off. They immediately turned back on, so the women called 911 and left the apartment.

Fire fighters confirmed that the women, who began to experience chest pain and dizziness, had carbon monoxide poisoning and urged them to go to the emergency department.

“People on social media ran with this narrative that ‘oh, they're so dumb for smoking in an apartment.’ But even the firefighters had no idea that the hookah coals could create carbon monoxide,” said Micheaux, who posted a video about her experience on TikTok that has been viewed nearly 5 million times. “My carbon monoxide detectors saved our lives. Had they not gone off, we would have just gone to sleep.”

After receiving oxygen treatment for five hours, the women went home to rest.

“It's so sad how many people commented on my TikTok saying they lost multiple loved ones to carbon monoxide poisoning,” Micheaux said. “Be aware and don't dismiss things, like I did initially.”

Can hookah cause carbon monoxide poisoning?

Yes — there have been dozens of published cases and many more reported incidents in the media of people experiencing carbon monoxide poisoning from smoking hookah in a variety of environments and circumstances.

A study that analyzed 265 patients referred to just one hyperbaric oxygen therapy center for CO poisoning from 2015 to 2018 found that 22% (58 people) were associated with hookah, and that hookah-associated cases increased year after year. In the last two years of the study period, hookah was the most frequent source of CO poisoning.

Smoke from tobacco and the charcoal used to heat tobacco produces high levels of the colorless and odorless gas, as well as heavy metals, tar, nicotine and other cancer-causing chemicals also found in cigarette smoke, according to the CDC.

Carbon monoxide can kill in minutes because it reduces the ability for blood to carry oxygen, starving your heart, brain and body and causing symptoms like headache, dizziness, weakness, nausea, vomiting, chest pain and confusion. The gas can poison anyone, but infants, older adults and people with anemia, chronic heart disease or breathing problems are more likely to get sick.

CO poisoning can happen so quickly that some people may become unconscious before experiencing symptoms. It can also happen even when smoking outdoors and via second-hand smoke exposure inside hookah lounges, for example, that may not be properly ventilated.

Drinking alcohol doesn’t exacerbate carbon monoxide poisoning, but it can impair your judgment and ability to recognize and respond to symptoms, said Dr. Thomas Waters, an emergency medicine physician at Cleveland Clinic.

Most people with CO poisoning will begin to feel better after about two hours of oxygen treatment, but mild symptoms can last for 24 hours, Waters said.

Long-term effects from CO poisoning are possible, Waters said, such as confusion, depression and difficulty focusing and concentrating.

Is hookah safer than cigarettes?

Hookah is often considered a safer alternative to cigarettes, which also release carbon monoxide, but evidence shows it may pose similar or more health risks.

People may inhale 100-200 times the amount of smoke during a one-hour hookah session than they would from a single cigarette, the CDC says, potentially exposing themselves to up to 9 times more CO and 1.7 times more nicotine.

Hookah alternatives, including electric products that turn liquids instead of charcoal into an inhalable aerosol, are growing in popularity, but much remains unknown about their health risks.

A 2019 study published in the journal Circulation found that carbon monoxide levels increased 9- to 10-fold more in young adults’ breath after smoking charcoal-heated hookah than after electrically heated hookah or cigarette smoking.

Other carbon monoxide sources in your home — and how to prevent poisoning

CO is found in fumes produced by gas stoves, portable generators, burning wood or charcoal, furnaces and lanterns, the CDC says.

Winter is the most dangerous time for carbon monoxide poisoning, as home heating systems run for hours.

More than 400 Americans die from unintentional CO poisoning each year, more than 100,000 go to the emergency department and more than 14,000 are hospitalized, according to the CDC. Most deaths occur in the colder months from November to February.

To prevent CO poisoning:

• Check or change the batteries in your carbon monoxide detector every six months, and replace it every five years.

• Have your heating system, water heater and any other gas, oil or coal burning appliances reviewed by a qualified technician every year.

• Keep vents free of debris to maintain proper ventilation.

• Never run a parked vehicle, generator, pressure washer or any gasoline-powered engine in an enclosed or partially enclosed space, such as a garage, even if doors or windows are open.

• Don’t use a charcoal grill, hibachi, lantern or portable camping stove inside a home, tent or camper.

• Have your chimney checked or cleaned every year, as debris can block air flow.

• Never use a gas range or oven to heat your home.

If you suspect carbon monoxide poisoning, call 911 right away.

This article originally appeared on USA TODAY: Can hookah cause carbon monoxide poisoning? These women learned the hard way.