BUCHAREST Romania declared "Code Red" on Monday as the death toll from a week-long heatwave rose to 18, Greece called a state of emergency, forecasting temperatures of 45 Celsius, and forest fires raged in Bulgaria.
Romanian Health Minister Eugen Nicolaescu said three Romanians had died in the last 24 hours and urged people to cancel outdoor travel in the hottest part of the day.
"Code Red will be enforced for July 24 in five southern counties and in the capital Bucharest," he told journalists after an emergency meeting. The government also banned outdoor work, including construction, in the hottest hours.
Sporadic blackouts hit parts of Bucharest, including the government headquarters, because of demand from energy-hungry air conditioners as temperatures soared to 42 Celsius (107 Fahrenheit).
In the previous 24 hours around 16,000 people suffering from the heat went to Romanian hospitals and 700 fainted in the street. Thousands of water wells have dried out and supermarkets have reported shortages of sparkling water.
Meteorologists forecast three days of rising temperatures in the region's second heatwave this year. More than 35 people died in Romania, Turkey and Greece in June when the mercury shot up to 46 Celsius.
In Greece, the Health Ministry activated an emergency plan to deal with possible mass hospitalisations and power outages.
"We have been on full alert since Friday, increasing the number of staff on duty," said Dimitris Pirros, national first aid centre spokesman.
A heatwave in 1987 caused hundreds of deaths in the Greek capital and authorities have since taken steps to protect the most vulnerable and elderly.
"A second heatwave in a month is certainly something rare," said the head of the national weather service, Dimitris Ziakopoulos. "Temperatures will start falling on Thursday."
Dozens of forest fires were raging across Bulgaria, causing the death of one man, and meteorologists said the weather was the country's hottest for 120 years, with temperatures hitting 42.6 degrees in the north.
Authorities in the southern town of Stara Zagora summoned the army and a special Russian aircraft to help put out some 20 fires which threatened the town and neighbouring villages.
Many municipalities introduced water rationing because wells were failing, while others sprayed water on streets and trees to prevent fires and offered free medical help and fresh drinks.
(Additional reporting by Sofia bureau, Renee Maltezou in Athens and Iulia Rosca in Bucharest)