Holiday visitors to the Greek Islands have been warned to stay cool this week as temperatures soar all over the Aegean.
Even locals have been told to stay out of the sun as weather experts report thermometers rising above the 40°C mark on the mainland with no sign of an end to the heatwave.
Temperatures have already topped 35°C this week in the country's two largest cities of Athens and Thessaloniki while other areas, including the Greek Islands have seen the mercury rise above the 38° mark.
It has been so hot in some mainland cities that many local councils have opened the doors of air-conditioned spaces to the general public.
It is much the same on the Greek Islands, although temperatures are a little lower at 35°C to 37°C, still hot enough for authorities to advise visitors not to stay out in the sun during the hottest part of the day.
Weather forecasters warn there will be no let-up in the heat until the weekend but predict that temperatures may still only fall a degree or two while humidity will remain high in the weak winds.
Advice to visitors includes drinking plenty of water, staying in the shade between noon and 3 pm and not to go walking without taking proper precautions.
Of course, holidaymakers expect hot and sunny weather in Greece; that is why they head out to Greek Island beaches in their thousands each year and August is notorious for long, hot sunny spells.
A similar heatwave sent temperatures soaring last year with temperatures topping 40°C in the shade in central Macedonia, Thessaly and large parts of the Peloponnese.
But the holiday islands were also affected with the southern islands of Crete and Rhodes suffering the highest daytime temperatures and the Greek General Secretariat for Civil Protection issuing warnings to holidaymakers to take extra care.
Holidaymakers again advised this year to wear light and comfortable clothes, hats and sunglasses and to eat light meals with an emphasis on fresh fruit and vegetables.
Health experts taking cool showers as frequently as possible and to stay hydrated by drinking plenty of cool water but not icy-cold and to avoid alcoholic, carbonated or caffeinated drinks during the hottest part of the day.
Although the worst may be over by the weekend, weather forecasters warn that rising humidity will make the atmosphere feel uncomfortable, especially at night, as winds stay weak with a lack of fresh sea breezes that normally sweep the islands at this time of year.