Twenty-one people are dead and 66 others have been hospitalised with exhaustion as soaring temperatures and high humidity hit Cairo and other parts of Egypt.
The victims, who all died on Sunday (local time), succumbed as temperatures reached highs of 47degC in conditions made less bearable by elevated humidity.
Fifteen people died in Cairo, four in the western province of Marsa Matruh and two in Upper Egypt's Qena province, health officials said. Those who died, including seven women, were all aged over 60.
Sixty-six people were admitted to hospital after suffering from exhaustion, including 37 who are still under observation.
"There is a big rise in temperature compared with previous years. But the problem is the humidity which is affecting people more," said ministry spokesman Hossam Abdel Ghaffar.
"Long exposure under the sun is a killer."
Meteorological officials confirmed temperatures in the capital and some parts of the country were higher than average.
"The temperature is higher by four to five degrees than what is usually seen and the humidity is very high this month," Waheed Soudi of the Egyptian Meteorological Authority said.
"The peak temperature in the shade was 38degC in Cairo on Sunday, which means it was 47degC under the sun or in places with bad ventilation."
On Monday, the temperature touched 37degC by late morning, with state media reporting that the heatwave was expected to last until the middle of August.