Amid extreme hot and humid weather conditions, the bodies of nine persons were brought to different hospitals in the city on Monday.
According to the in-charge of Edhi Centre, the bodies were found lying abandoned in different parts of the city, adding that most of the deceased appeared to be drug addicts.
With severely weakened immune system, drug addicts could not bear extreme weather conditions, said Psychologist Dr Qazi Humayun Rasheed while referring to the recent casualties.
Similarly, sweltering weather in Karachi claimed 20 lives on Thursday.
Rescue officials had said they received eight more bodies from different areas of the city that day as well, bringing the total number to 20.
The bodies appear to be of drug addicts, they said adding that the bodies had been shifted to the Civil Hospital, Jinnah Hospital and Abbasi Shaheed Hospital.
They said three bodies were found in the Lyari area of Jehanabad while one body each was recovered from Chundrigar Road, Clifton, Malir, Quaidabad and Super Highway.