The Whitefield couple who suffered suspected carbon monoxide poisoning on Christmas remained hospitalized Thursday, but their health is improving, according to the Lincoln County Sheriff’s Department.

Lt. Rand Maker said he spoke with the family of the couple on Thursday.

A neighbor went to the couple’s Heath Road home Wednesday to check on them and found them unconscious, Maker said.

The man, 83, was flown by helicopter to a hospital in what Maker described as potentially life-threatening condition. Maker said he doesn’t know which hospital the man was taken to.

He said the woman, 84, was taken to MaineGeneral Medical Center in Augusta by ambulance.

No other information on the couple was available.

Emergency responders from the sheriff’s department and the Whitefield Fire Department found a generator in an attached garage, which was directly beneath a part of the home, according to Maker.

He said it was another example of the importance of keeping generators outdoors, where the carbon monoxide fumes have a chance to dissipate.

A man in Knox was killed Tuesday morning while refueling a generator in his garage.

The Centers for Disease Control and Prevention advises that generators should never be used inside a home, basement, garage or outside near an open window. More than 400 people die in the U.S. every year from accidental carbon monoxide poisoning, according to the CDC.