A four-day heat wave has killed more than 780 people in Karachi as the government declared a holiday in the southern Pakistani city to encourage people to stay home.
The heat wave has coincided with severe electricity cuts and the holy month of Ramadan, when most Muslims do not eat or drink during daylight hours. Many of the deaths, among the elderly and poor have been caused by dehydration.
Anwar Kazmi, a senior official with the Edhi Foundation, a private charity, told the Reuters news agency that "the heat wave death toll has reached close to the 800 mark in the last four days."
The charity runs a network of ambulances, clinics and morgues to bridge the gaps in an overburdened and poorly funded public health system in the city of 20 million people, home to Pakistan's main stock market, central bank, and biggest port.
Government health officials did not return calls seeking comment.
Many of Karachi's wealthy have generators to run air conditioners to beat the heat, which reached 44 degrees Celsius over the weekend. Public services in Pakistan, a nuclear-armed nation of 190 million people, are starved of resources because of endemic tax evasion.