The 33-year-old woman was found in a roach-infested, garbage-filled room in the house on Woodlawn Avenue. The temperatures had reached over 100 degrees in the room, authorities said.
The disabled woman suffered from cerebral palsy and Down syndrome.
She was found unresponsive in a second-floor bedroom by her mother around 12:30 p.m., police said.
According to authorities, no one called 911 for more than two hours so they could rearrange furniture in the home and move the woman to the front door before EMS arrived, apparently in an attempt to conceal the horrific condition of the home.
Police say both the first and second floors were infested with roaches, flying insects and rotting food. The toilet on the second floor was broken and full of feces. Police added that the ceiling had collapsed and beams were visible in the victim's bedroom.
Her sister, Helene Hutchinson, 45, and her mother, Florence Garland, 78, have been charged with neglect of an elderly or disabled person.
Authorities believe the oppressive heat played a role in the woman's death. They were awaiting the results of an autopsy.
Police said Hutchinson owns the home, which has been in foreclosure for the past two years.