The four-day death toll from the intense heatwave in Karachi has risen to 475, Pakistan's Geo TV said on Tuesday.

According to Sindh Health Minister Jam Mehtab Hussain Dahar, 181 patients have died in Jinnah Hospital, 62 in Civil Hospital, 68 in Abbasi Shaheed Hospital, 12 in New Karachi Hospital and over two dozen have breathed their last in private hospitals across the city.

There are reports of more people dying at homes due to severe heat and dehydration. According to officials, people over the age of 40 are more susceptible to the heatwave.

At the Edhi morgue in the city bodies have been received and there is no longer any space left to keep them.

Residents of the city have not only been faced with the intense heatwave but also prolonged power outages during the holy month of Ramadan.

National Disaster Management (NDMA) spokesman Ahmed Kamal said the government had asked the army and paramilitary Rangers to help relief efforts which will include setting up heatstroke treatment centres around the city.

Coping with the scorching heat has been made harder by the power cuts that are a daily feature of life in Pakistan.

The government of Sindh has imposed a state of emergency at all hospitals, cancelling leave for doctors and other medical staff and increasing stocks of medical supplies.