The ailing Thai King Bhumibol Adulyadej briefly left the hospital in Bangkok Monday for the first time since last May. Bhumibol, 88, visited his Chitralada Palace "for a change in atmosphere," an anonymous palace source told Reuters. He was set to go back to Siriraj Hospital later in the day.

Thais stood on the street near the medical center to support the king, whom they regard as a father figure amid chronic political instability. "This is the best opportunity in my life to see him," resident Nuananong Sripai told Reuters. "I'm worried about his sickness and hope he will get better soon."

Bhumibol is the world's longest-reigning monarch and chief of state, but he's spent most of the past six years in the hospital. The palace released a statement Sunday revealing he has been undergoing treatment recently for a fever, lung infection, blood infection and knee problems. "Currently, the king's fever has eased, but his breathing is occasionally faster than normal, while his pulse and blood pressure are normal," the Associated Press quoted the Royal Household Bureau saying.

In recent years, the king, whose official title is Rama IX, has battled flu, pneumonia, intestinal inflammation, hydrocephalus and bleeding in his brain, according to Turkey's Anadolu Agency. Before Monday's re-emergence from the hospital, he was last seen in public in September. Bhumibol even missed his Dec. 5 speech marking his birthday celebration — the second consecutive year he's done so. But he did appear on television Dec. 11 during a swearing-in ceremony for judges. 

The king's health is a touchy subject for many reasons, among them that people in Thailand are legally prohibited from criticizing the royal family under lese-majeste laws. Also adding to international concern around Bhumibol's condition are fears over the succession. Crown Prince Vajiralongkorn, the king's 63-year-old son, is widely unpopular.

"I don't know what to think," banker Thaweewat Chongsuanoiy told AP last month. "He has been the person that holds the people together; without him, people would be lost."