A woman was critically injured early Sunday in one of three fires that broke out in residential buildings in Prince George’s County. A county fire department spokesman said two of the blazes might be linked to efforts to furnish heat during the weekend’s chilly weather.

The fire in which the injured woman was found unconscious was reported about 3 a.m. in a two-story house on Peachleaf Court in Upper Marlboro, said county fire department spokesman Mark E. Brady.

He said the woman had no pulse and was not breathing when found. She was suffering from burns and smoke inhalation.

The cause of that fire was thought to be accidental, but no details were available.

Two other fires may have been linked to efforts to cope with the weekend’s low temperatures, Brady said. One occurred shortly before 1 a.m. in the 5200 block of Palco Place in the College Park area.

It was found after firefighters were alerted to smoke that had drifted over a portion of the Capital Beltway, Brady said. He added that the fire spread rapidly up from the basement of a two-story single-family home and burned through the roof.

The cause is still being investigated, but it appeared that the fire may have been connected to the initial use of the house’s furnace, Brady said.

He said the third fire was reported about 8:30 a.m. in a three-story apartment house in the 3500 block of Windom Road in the Brentwood area. He said investigators thought a space heater in a second-floor unit ignited nearby material.

Brady said neighbors who saw the fire went into the building and alerted residents, who escaped without injury.