There was something wicked in the air at the River Ridge Tap House in Clemmons, N.C., on Saturday night, and it was not the twang of Southern rock. Lonnie Wimmer, at the restaurant around 9 p.m. for a friend’s birthday celebration, began to notice the other patrons behaving oddly.

“People were starting to act a little weird,” Wimmer said to Fox 8. “Heads hurting, people holding their belly going to the bathroom a lot. Some of the adults were acting kind of nauseated, sick.”

Wimmer, too, became nauseated. Though the customers complained of piercing headaches and twisting guts, the fault did not lie with River Ridge Tap House’s draft selection.

He recognized the symptoms: Carbon monoxide was filling parts of the restaurant. When emergency responders later measured the carbon monoxide, they found gas in amounts more than five times the level deemed safe.

Wimmer knew whom to call — he was, after all, a firefighter with the nearby Lewisville Fire Department. All told, half-a-dozen ambulances would arrive on the scene, as well as one of the only eight medical emergency buses in the state of North Carolina. Wimmer described to WXII 12 the grim possibility had emergency crews not arrived: A sick person could have gone home, he said, “went to sleep and never could have woke up.”

Exposure to too much carbon monoxide disrupts blood cells’ ability to carry oxygen throughout the body; the molecule binds to hemoglobin with an affinity some 200 to 250 times greater than that of oxygen. Symptoms of carbon monoxide poisoning vary, but include vomiting, dizziness, chest pain and mental changes like confusion. If left untreated, inhaling the gas can be fatal. The Centers for Disease Control and Prevention reported that between 1999 and 2010, an average of 430 people died from accidental carbon monoxide poisoning in the United States.

“It was not fun!” said customer Stephanie Miner to WFMY-TV. “It just scares you to think, ‘Oh my gosh what is happening to me? Did I get infected by that much? What’s going to happen?’”

Forsyth County emergency responders evacuated the restaurant. Of the 100 or so customers at the taproom Saturday night, 31 people were treated. The gas hospitalized more than a dozen people, who were transported to area medical centers in the ambulance bus.

“On the scene we needed a place to keep them out of the cold and give them oxygen,” MA Barker, the Forsyth County EMS logistics officer, told WFMY.

A heating unit malfunctioned at the restaurant, releasing the colorless and odorless gas into the restaurant, Lewisville Fire Department Assistant Chief Steve Williams said in an interview with WVTM 13.

“We are extremely confident that was the main source of the leak,” Williams said to the Winston-Salem Journal. “The heating unit for that room malfunctioned and stopped burning cleanly, which can happen to any of those units.”

Under North Carolina law, homeowners and landlords are required to install carbon monoxide detectors in dwellings, but not in restaurants. The Winston-Salem Journal reported that the restaurant did not have a detector installed.

“We deeply regret what happened,” said Jenna Edwards, a manager with the River Ridge Taproom, to WFMY. “I feel sorry for everybody that was back here.” The restaurant reopened Sunday morning after the source was fixed.

The incidence of carbon monoxide poisoning spikes during hurricanes, snowstorms and other severe weather events, when individuals use gas-powered generators after electricity fails. For this reason, the CDC advises against operating gas- or charcoal-burning devices like grills and generators indoors, even in a garage or near a window.

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