Thailand's royal palace says 87-year-old King Bhumibol Adulyadej is recovering from a high fever and chills but is still being treated for the bacterial infection that caused it.

The announcement by the royal household, broadcast Monday on the nightly royal television news program, said doctors have been treating the infection with antibiotics and saline solution, and giving the king an oxygen-air mix when needed to help his breathing. He also had low blood pressure and a high pulse rate, which it said returned to normal on Monday.

The last public appearance of the king, the world's longest reigning monarch, was on Sept. 1, when he did a short tour in wheelchair of the Bangkok hospital that been his home for most of the past six years.