Slovenia's President Janez Drnovsek, who has long been ill with cancer, collapsed during an official ceremony on Saturday evening and was taken away in an ambulance. His spokeswoman said he later recovered.
"The president feels better. He assessed that he doesn't need medical treatment and is now at his home," Janja Lah, Drnovsek's spokeswoman said.
When he collapsed, Drnovsek had been standing in the front row at an open-air ceremony celebrating the 15th anniversary of Slovenia's independence from the former Yugoslavia, in Republic Square in downtown Ljubljana. Evening temperatures were around 27 degrees Celsius.
The 56-year-old president also had a hectic schedule on Saturday, with a number of meetings and other protocol duties.
Drnovsek had a cancerous kidney removed in 1999 and acknowledged last year that doctors diagnosed what he described as "formations" on his lungs and liver in 2001. It is widely believed those were secondary cancers.
He has said he decided to abandon medical treatment and is pursuing a healthy lifestyle and diet instead. He moved from Ljubljana to a remote village where he eats only healthy, vegetarian food and bakes his own bread.
In a 2005 interview with Croatian daily Nacional, he said he decided to abandon treatment after realising that neither traditional nor alternative medicine could cure him. "For me, the disease simply doesn't exist anymore," he told Slovene reporters later.
Drnovsek was elected Slovenia's president in 2002, after being the country's prime minister for a decade.