Over the past week, three search and rescue operations have been started for tourists who have gone missing during treks on far-flung islands, including one for the popular TV presenter Michael Mosley, who was found dead on the island of Symi.

In recent days, emergency services have also been called out to two other far-flung islands, Samos and Amorgos, to look for an elderly Dutch man and a US national who disappeared on hiking trails.

Eric Calibet, 59, a retired Los Angeles police officer and regular visitor to Amorgos, was last seen on Tuesday making a solo trek across the Cycladic isle. He had set out at 7am to hike for four hours, on a day when temperatures were slated to exceed 37C. By late Thursday, nearly 48 hours after the friend he was staying with alerted police about his failure to return, Calibet was still missing. His last known contact is believed to be a message he sent from his mobile phone to his sister.

A search operation on Samos – involving a rescue team, four drones, a sniffer dog brought in from Athens and a Frontex EU border agency helicopter – has also failed to find the 74-year-old Dutch national, who had similarly embarked on a five-hour hike when he vanished.