(CNN)The August heat is proving a killer in Philadelphia.
The heat is being blamed as contributing factor in the deaths of at least four people, all of whom were suffering from other medical issues, Jeff Moran of the city's Public Health tells CNN.
-- A 72-year-old man from West Philadelphia, who also had diabetes, hypertension and obesity, died Monday.
-- A 59-year-old man died Sunday. He previously suffered from diabetes and congestive heart failure.
-- A 67-year-old woman from the Port Richmond neighborhood who had diabetes and congestive heart failure died between Thursday and Saturday.
-- An 82-year-old woman from North Philadelphia who had heart disease and hypercholesterolemia died between Thursday and Saturday.
It was not immediately known whether the victims had air conditioning or whether the units were working.
CNN Weather advises that the excessive heat warning expires Tuesday evening, and that the high for the rest of the week is expected to be about 90 degrees.
The high temperatures last Thursday through Sunday were all 95 degrees and above. The highest was 98.