Three tourists, including one American, have died and two others remain missing in Greece as the country faces extreme temperatures amid a string of heat waves that have prompted authorities to close schools and historical sights. 

The body of an American from New York, who had been missing since Tuesday, was found Sunday on the island of Mathraki, his family confirmed to CBS News on Monday. Toby Sheets was found dead the previous day on a beach on the island, his cousin Greg Sheets and father Ronnie Sheets said. 

His father said Sheets was "a very hard worker and he was doing what he loved, training horses," and added that he was loved and "will be dearly missed."

Another body was found Saturday on the island of Samos, where a Dutch hiker had been missing for a week.

Earlier this month, the body of British television personality Dr. Michael Mosely was discovered days after he disappeared during a walk on the island of Symi.

Albert Calibet, 59, a retired police officer who holds duel U.S.-French citizenship, was still missing Tuesday after he set out on a hike alone a week earlier on the island of Amorgos. His brother Oliver, in Greece with a small group of other friends and family to help with search efforts, posted a video Monday on YouTube pleading for more help to find Calibet.

He said Greek authorities appeared to be doing what they could with limited resources, but decried the U.S. government for not sending more assets to help in the search.

Two French women were also missing, including one who called the owner of the guest house where she was staying on Friday to ask for help, according to the Reuters news agency. Ilias Gavanas, the guest house owner, told Reuters the woman had sent him a selfie and message early Friday morning indicating that she had fallen. 

He told Reuters that he replied to her in both French and English, asking her to provide her location and urging her to call the European emergency number 112. He said he also alerted the local police.

A Greek rescue operation leader said tourists appeared to be unaware of the risks they face walking in the extreme heat.

• Heat stress can turn deadly even sooner than previously thought

"We saw a couple [of tourists] walking a trail in 41C [105.8F] without hats," Dimitris Katatzis told local media, according to Britain's Independent newspaper. "It defies logic."

Greece has seen extreme temperatures arrive earlier in its summer season than ever before this year, according to meteorologist Panos Giannopoulos.

"This heat wave will go down in history. In the 20th century, we never had a heat wave before 19 June. We have had several in the 21st century, but none before 15 June," Giannopoulos told Greek state television channel ERT.

The heat has prompted warnings from the government and, last week, the Acropolis and other tourist attractions were closed as winds from North Africa pushed temperatures in Athens to around 109 degrees Fahrenheit. Schools and day care centers were also shut, and firefighters remained on high alert to respond to any blazes.

• Scorching heat waves "virtually impossible" without climate change, experts say

"The early start of the heat waves, combined with the dry winter, has led to a very difficult fire season," Vassilis Kikilias, Greece's Minister of Climate Crisis and Civil Protection said, according to the Independent newspaper.

The high temperatures have hit Greece after a European climate watchdog, the Copernicus program, said data from 2023 showed the continent had experienced a record number of days of "extreme heat stress," meaning temperatures felt like about 114 degrees Fahrenheit or higher. 

Copernicus said heat-related mortality in Europe had risen by around 30% over the past two decades.

In:
• Travel
• Climate Change
• Heat
• Heat Waves
• Global warming
• Greece
• Excessive Heat Warning
• Heat Wave
• Missing Person
• Mediterranean Sea

Haley Ott

Haley Ott is the CBS News Digital international reporter, based in the CBS News London bureau.

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