A cool wind from the sea and pre-monsoon rains brought the first signs of respite to southern Pakistan on Wednesday as the death toll from a scorching heat wave climbed to 838 -- a high figure even for a nation accustomed to sizzling hot summers.

Temperatures in hard-hit Karachi, the country's largest city and its commercial hub, dropped to 34 degrees Celsius (93.2 degrees Fahrenheit), meteorologist Abdur Rasheed said.

The drop likely marked the end of the heat wave that began on Sunday. Hospital officials said admittances were lower on Wednesday than in previous days, when dehydrated patients lay in corridors and outside on the streets.

The port city has been in the epicenter of the heat wave, dubbed worst in at least a decade, with temperatures reaching 45 degrees Celsius (113 degrees Fahrenheit). Hours-long power outages, little running water and the majority of people fasting for the Muslim holy month of Ramadan had worsened the situation further.

Karachi is the capital of southern Sindh province and is home to some 20 million people. It suffers under an inefficient power grid and a shortage of potable water. The power outages have also affected the city's sporadic water supply, forcing those who can afford it rely on tankers of water being delivered to their homes.

Maj. Gen. Asghar Nawaz, chairman of the National Disaster Management Authority, told reporter that in Karachi alone, 800 people died as a result of the heat wave.

Another 38 people died in various parts of Sindh province, he said, warning that the death toll could rise further in the coming days because many of the sick are in critical condition.

He said authorities, with help from the army, were providing medical care to the Karachi victims. He added that Pakistan could face cyclones and harsh weather in the future as well because of climate change.

During the heat wave's worst moments, Karachi residents tried to find running water to cool off at public taps or broken pipes. Some bathed with their clothes on, while others washed their hands, faces and heads. As power outages rolled across the city, women and children walked down roads looking for shelter after leaving their small, hot homes.

"We're forced to sleep in the streets," resident Muzafar Khan said.

Political parties running the southern province and the federal government blamed each other for the disaster while they debated the issue in parliament Wednesday.

Some pointed out that there were people in Karachi who could not find cars to carry the coffins of their dead to the cemetery and even if they made it to the cemeteries, gravediggers would overcharge them for their services.

"I literally wept when I heard a poor man didn't have money to pay a grave digger," opposition lawmaker Abdul Rashid Godil said.