A Pakistani man shifts a heatwave victim to a hospital in Karachi on June 22, 2015. Nearly 200 people have died in a heatwave in southern Pakistan, officials said as the government called in the army to help tackle widespread heatstroke in the worst-hit city Karachi. AFP PHOTO / ASIF HASSAN

A heat wave has killed almost 450 people in Pakistan’s south over the past three days, with paramilitary forces beginning to set up emergency medical camps in the streets, health officials have said.

Most of the deaths have been in the southern port city of Karachi where temperatures in the surrounding Sindh province reached up to 45C on Saturday.

Hospitals have been swamped with people suffering from heatstroke and dehydration, while repeated power outages have left many without air conditioning or running water.

The electricity grid, run by a private company K-electric, has been overwhelmed as people switch on fans and air conditioners, and as families begin to cook at the same time during the month of Ramadan.

Electricity cuts in turn crippled Karachi’s water supply system, hampering the pumping of millions of litres of water to consumers, the state-run water utility said.

Al Jazeera’s Kamal Hyder, reporting from Islamabad, said the official death toll had risen sharply to 445 by Tuesday, as many of those who died were already in a critical condition when they were admitted to Karachi hospitals in previous days.

“Most of these people are very poor because there are lot of people who are living on the streets, the victims are elderly,” he said.

Our correspondent said the provincial government had been criticised by opposition parties for poor management of the crisis.

On Tuesday, Pakistan’s paramilitary Rangers force set up medical camps at several points in Karachi where they were providing water and anti-dehydration salts.

“The opposition is now criticising the government in Islamabad, however it is the opposition that is ruling the province of Sindh,” Hyder said.

“The blame game is going on but the government did not issue any early warnings to tell the people to take care and because of the power outages, the situation became worse.”

While temperatures in Karachi itself touched 44C in recent days, up from a normal summer temperature of 37C, meteorologists said rain was on its way.

“We are anticipating a sea breeze will set in some time [on Tuesday night]. The temperature will come down as the monsoon rain enters the Sindh coast, bringing rain to the city,” Ghulam Rasool, director general of the Meteorological Department, said on Tuesday.

Last month, soaring temperatures during a weeks-long heat wave caused water shortages in thousands of villages in India, killing at least 1,826 people.

The heat wave covered a huge swath of India from Tamil Nadu in the south to the Himalayan foothill state of Himachal Pradesh. (Al Jazeera)