More than 40 female inmates at the York County Prison are being treated for carbon monoxide poisoning.
Warden Mary Sabol said 40 to 45 inmates in the female dormitory became sick Wednesday night and that officials are investigating the cause. Ninety women live there.
"It appears that everyone is going to be OK, said Sabol, adding that the gas levels in the dorm were dissipating Thursday morning.
Emergency management officials in Dover said the patients are being treated at York and Memorial hospitals.