That man has been identified as 67-year-old Edward Green.
Medics were called to the 900 block of Carver Street in the Lawncrest section of Philadelphia around 2:00 p.m. on Tuesday for a report of an unresponsive man.
Once there, they found Green who did not have a pulse.
He was rushed to the hospital where he was later pronounced dead.
Medics who attended to Green said they believed his symptoms were consistent with heat-related problems, but further investigation has ruled out heat as a cause of death. An exact cause has not been released.