KARACHI: At least 830 people have perished in Sindh since Saturday as the province languishes in the grips of a searing heatwave.

The total death toll at Karachi's Jinnah Postgraduate Medical Centre has risen to 295 since Saturday. The combined death toll at Abbasi Shaheed Hospital and other Karachi Municipal Corporation-run hospitals has peaked at 140. Civil Hospital Karachi has seen 110 dead, while 58 have perished at Liaquat National Hospital.

The Emergency Cardiac Centre in Shah Faisal Colony has seen at least five deaths since Saturday, and Sindh Government Hospital Liaquatabad and New Karachi have seen 10 and 23 dead respectively.

Take a look: Relentless heatwave takes another 337 lives

On Sunday, at least 136 deaths were reported, while on Monday 309 were reported dead. On Tuesday, 311 were reported dead in Karachi while 26 died in other parts of Sindh.

Temperatures in Karachi are expected to peak at 36 degrees Celsius on Wednesday as a relatively cool sea breeze started blowing on Tuesday evening.

The weather outlook for Sindh according to the Pakistan Meteorological Department is hot and humid in most parts of the province, while rain is expected in various parts of Mirpurkhas division and isolated areas in Sukkur, Larkana, Hyderabad and Karachi.

Winds have shifted to the southwest, blowing cooler air into the port city from the Arabian Sea, and the Pakistani Met Office has predicted rain, which would bring lower temperatures.

The government has demanded urgent action to deal with the crisis, and the administration in Sindh province declared Wednesday a public holiday to encourage people to stay indoors out of the sun.

Some residents on Tuesday took to hosing each other down with water to avoid collapsing from heat stroke.

A state of emergency is in force in hospitals which are struggling to cope with the 3,000 people affected by heatstroke and dehydration.

The change in weather will come as welcome relief for the economic hub, where maximum temperatures have hovered around 44-45 degrees Celsius since Saturday.

The National Disaster Management Authority has been setting up dedicated heatstroke treatment centres to try to cope with the volume of patients.