Former President George H.W. Bush will spend Christmas in a Texas hospital after developing a fever and weakness following a monthlong, bronchitis-like cough.

Bush's spokesman Jim McGrath said Monday that doctors remain "cautiously optimistic" the 88-year-old will recover, but they want to keep him in the hospital.

A hospital spokesman had said last week that doctors expected Bush to be released in time to spend Christmas at home.

McGrath says Bush came down with a fever last week. McGrath says Bush has largely overcome the painful, lingering cough that initially brought him to the hospital on Nov. 23.

McGrath says he does not know what caused the fever or the weakness.