Over 30 people hospitalized after carbon monoxide leak at Pennsylvania day care center

More than 30 people, including children, were hospitalized Tuesday after a malfunctioning heating unit caused a carbon monoxide leak at a Pennsylvania day care center, officials said.

The leak happened at Happy Smiles Learning Center in Allentown, about 60 miles north of Philadelphia.

St. Luke’s University Health Network, which has two hospitals in Allentown, admitted 13 patients – 10 children and three adults – spokesperson Sam Kennedy told USA TODAY. All were stable, Kennedy said.

Two emergency rooms in the Lehigh Valley Health Network received 17 children and two adults who were also listed as stable, spokesperson Brian Downs said in an email.

First responders originally went to the day care center Tuesday morning to answer reports of an unconscious child, Allentown Fire Department Capt. John Christopher said. When they arrived, atmosphere monitors alerted them to high levels of carbon monoxide, which is poisonous and fatal in high enough quantities.

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Natural gas and electric utility company UGI Utilities arrived at the day care center just before 8 a.m., according to spokesperson Joseph Swope, who said the incident was caused by "a malfunctioning heating unit, as well as a blocked venting system."

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“We have multiple people on site doing precautionary checks of the area,” he said, adding people were evacuated due to safety concerns.

Multiple ambulances responded to the scene, which was cleared later Tuesday morning, Christopher said.

Those hospitalized experienced symptoms such as headaches, dizziness and nausea, and several people were unresponsive before getting to the Lehigh Valley Health Network hospitals, pediatric emergency medicine chief Andrew Miller said in a statement.

"All the patients had elevated levels of (carbon monoxide) in their blood," Miller said. "The levels ranged from three to 10 times higher than what’s deemed normal."

Carbon monoxide incidents rise during the cooler months as people turn on their heating systems, Swope said. The colorless and odorless gas can deprive vital organs of oxygen when inhaled, according to the Occupational Safety and Health Administration.

“We always urge people to take precautions and identify signs of carbon monoxide, especially if the heating system hasn't been checked and it's been off since the spring,” Swope said.

This article originally appeared on USA TODAY: Carbon monoxide leak at learning center in Allentown hospitalizes 30