Local morgues overflowed with the dead and overwhelmed hospitals struggled to aid those clinging to life.
Temperatures reaching 45 degrees Celsius (113 degrees Fahrenheit) began scorching Karachi over the weekend.
Hours long power outages, typical in Pakistan, also struck the city, leaving fans and air conditioners inoperable as the majority of people in the Muslim country abstain from food or water during the holy month of Ramadan.