The death toll from an ongoing heatwave in Pakistan's southern Sindh province has passed 700, local media said, as mortuaries reached capacity.
Dawn newspaper said at least 744 people had died in Karachi and 38 in other areas, citing a government official.
The Edhi Welfare Organisation told the AFP news agency that their morgues had received hundreds of corpses and were now full.
Officials have been criticised for not doing enough to tackle the crisis.
"More than 400 dead bodies have so far been received in our two mortuaries in past three days," Edhi spokesperson Anwar Kazmi told AFP. "The mortuaries have reached capacity."
On Tuesday as temperatures reached 45C (113F), Pakistan's PM Nawaz Sharif called for emergency measures and the army was deploying to help set up heat stroke centres.
There is anger among local residents at the authorities because power cuts have restricted the use of air-conditioning units and fans, correspondents say.
Matters have been made worse by the widespread abstention from water during daylight hours during the fasting month of Ramadan.
On Tuesday, the National Disaster Management Authority (NDMA) said it had received orders from Mr Sharif to take immediate action to tackle the crisis.
This came as Sindh province Health Secretary Saeed Mangnejo said 612 people had died in the main government-run hospitals in the city of Karachi during the past four days. Another 80 are reported to have died in private hospitals.
Many of the victims are elderly people from low-income families.
Thousands more people are being treated, and some of them are in serious condition.