Heatwave is an extreme weather condition and the deadliest type of weather phenomenon that is characterized by a prolong period of excessively hot weather with or without high humidity. According to World Meteorological Organization “a heat-wave occurs when the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature by 5°C”.
Hot weather is not unusual during the summer season throughout Pakistan; however, the high temperatures were made worse by frequent power outages that not only aggravated the heat but also crippled the city’s water supply system, hampering the pumping of millions of gallons of water to consumers. Due to global warming, it is suggested that “megaheatwave” will become increasingly more common in future (up to 10 times more likely over the next 40 years).

A sever heat wave struck the country in June 2015, which has caused high number of causalities especially in Karachi. Most of the country was under the grip of heat wave during 17 to 24 June. As on 20th June, high temperatures were recorded in the southern parts of the country. The temperature ranged from 49°C in Larkana and Sibi to 45°C in Karachi. In southern Punjab, 40°C was recorded in Multan, whereas several areas of the Balochistan province were also affected where temperature touched 49°C in Sibi and Turbat.

According to news and reports, because of this heat wave, more than 1000 death cases due to heatstroke were reported in Karachi, Hyderabad, Noshero Feroz, Dadu, Badin, Thatta and Tharparkar. Deaths occurred mostly in the poor areas of Karachi and mostly they were working class factory workers who came from the low-income Landhi and Korangi areas of Karachi and they work around heaters and boilers in textile factories and there is eight to nine hours of scheduled power outages in these areas.