The Health Ministry advised Greeks on Tuesday to avoid going out into the sun over the next few days after the National Meteorological Service (EMY) warned of a heat wave.
EMY said that temperatures would rise by the weekend, reaching as high as 41 Celsius (105 Fahrenheit) in some parts of Greece.
“It will last for two to three days, which is why we issued an emergency bulletin,” said EMY official Angeliki Marinaki.
The weather service believes that temperatures will start to drop on Saturday afternoon, aided by northerly winds.
The Health Ministry said it had advised hospitals and health centers to be on alert for patients suffering from effects of the heat.