One cold morning last month, a carbon monoxide detector began beeping in a Bridgeville home.
The residents weren’t sure how to react.
Should they run out of the house? Should they investigate the source of the problem? Should they call somebody?
Perplexed, the homeowners consulted the internet, and that’s when a dangerous situation got even more dangerous.
When you type a question into Google, the search engine strives to give you the best-matching answer as soon as possible.
So if you search for “What to do if carbon monoxide detector goes off,” you’ll see something like this:

Other top-ranked articles recommend checking the detector’s batteries. Some sources suggest resetting the alarm to make sure it’s working correctly.
This is all bad advice, said Bridgeville fire chief Bill Chilleo.
“Do not go on the internet,” he said. “Call 911, and get out.”
(The U.S. Product Safety Commission, which ranks quite low on Google, agrees with Chilleo).
In this case, the family—two adults and two children—followed the internet instructions and let some fresh air into the house. A short while later, the alarm went off again.
This time, they called 911. When Bridgeville volunteer firefighters arrived, they checked the home’s carbon monoxide levels and found readings of 70 parts-per-million on the second floor.
“That’s where [the family] was sleeping,” Chilleo said.
CO levels that high won’t quickly kill a healthy adult, but they can cause nausea, fatigue, and headaches. By comparison, OSHA limits workers to no more than 50 parts-per-million every eight hours.
After some investigation, Bridgeville firefighters pinpointed the source of the problem—a faulty furnace.
In a stroke of amazing luck, the residents had installed their CO detector just two days prior.
“They’re very lucky at that house, because you can’t see, taste, or smell CO,” Chilleo said. “We do recommend CO alarms, and it did save them.”