Former President George H.W. Bush is in intensive care and has a "stubborn fever," a spokesman said.
Bush's fever is slightly elevated, Jim McGrath told CNN Wednesday. The 88-year-old former president has been at Methodist Hospital in Houston for a month now.
McGrath also said he "is alert and conversing with medical staff, and is surrounded by family."
Bush was initially receiving treatment for complications related to bronchitis. But he began experiencing other complications including a fever last week.
On Christmas Day, Bush was visited by family. Former president George W. Bush is expected to visit him soon.
"His mood is relentlessly positive and includes humorous banter with his doctor," McGrath said, according to CNN.
George H.W. Bush served as the 41st president of the United States. He previously served as vice president.