Division Chief Michael Cox said the firefighter, whose name was not given, suffered burns to his ears and neck and was taken to the burn unit at Johns Hopkins Bayville Medical Center.
The three occupants of the house escaped without injuries, he said.
Cox said it took 51 firefighters about an hour to get the fire under control. He said the fire caused about $550,000 in damage and was believed to have been accidental. An investigation continues, Cox said.