Search Underway in Greece for British TV Doctor Michael Mosley

Greek authorities on Thursday said they were searching for Michael Mosley, a prominent British journalist and television presenter who had gone missing a day earlier while on a walk on the island of Symi.

Mr. Mosley, 67, was reported missing by his wife, Clare Bailey, on Wednesday afternoon, according to Constantina Dimoglidou, a spokeswoman for the Greek police. The couple had arrived in Symi on Tuesday, planning to stay for a week.

“We’re looking everywhere for him,” Ms. Dimoglidou said, adding that the local fire service and volunteers were involved in the search. The Greek fire service on Thursday said a team of six firefighters was looking for a missing foreign national on Symi, part of the Dodecanese islands in the Aegean Sea, and said drones had been sent from the nearby island of Rhodes.

Mr. Mosley told friends on Wednesday afternoon that he was going to walk about two miles from the Agios Nikolaos area back to the main town of Symi, where the couple was staying, according to Ms. Dimoglidou. He was last seen by a witness at a bus stop in Pedi, about halfway between the two locations, and did not have his cellphone on him when he disappeared, she said.

It was possible, she said, that Mr. Mosley had become dizzy from the heat. Temperatures in Symi have hovered around 95 degrees Fahrenheit this week, and the weather authorities in Greece had urged vigilance over the risk of high heat.

“It’s rugged terrain with high spots, so it’s possible that he fell,” Ms. Dimoglidou said. His disappearance also spurred a call for information in a local Facebook group, in which a post said that Mr. Mosley had set off at around 1:30 p.m. and never appeared at his accommodation.

Mr. Mosley trained as a doctor before becoming a documentary maker and a science journalist who dispensed advice on diet, fasting and other health habits. He became famous for his myth-busting work on diet and is widely known as a proponent of intermittent fasting, writing several books on the subject.

A longtime producer and presenter for the BBC, he is the host of the broadcaster’s “Just One Thing” health podcast, and was nominated in 2002 for an Emmy for “The Human Face,” a series examining the science behind beauty.

More recently, he released two series with the British Channel 4 broadcaster investigating obesity in Britain and the nutrition behind the grocery shopping of everyday consumers.