The heat was getting to Marguerite Boudreaux, 85, in Gretna, a suburb of New Orleans.
"I have a daughter who is an invalid and then my husband is 90 years old, so he's slowing down a lot," she said, red in the face as she stood in the doorway of her house, damp and musky from the lack of air conditioning.
Isaac dumped as much as 16 inches of rain in some areas, and about 500 people had to be rescued by boat or high-water vehicles.
At least five deaths were reported in Louisiana and Mississippi.
The latest two victims, a man and a woman, were discovered late Thursday in a home in the hard-hit town of Braithwaite, south of New Orleans. Authorities said deputies went to search for the couple after someone reported they had apparently not escaped the flooding. Their names were not immediately released.
An unidentified man died in a restaurant blaze in Gretna that firefighters could not control because of Isaac's strong winds Wednesday. Another man died falling from a tree during the storm and a tow truck driver in Mississippi was killed when a tree crushed the cab of his truck.
On Grand Isle, a barrier island on the Gulf, the town pumped away water. Sections of the only road to town had washed out.
On a street turned river in Reserve, on the east bank of the Mississippi River, two young men ferried their neighbors to the highway in a johnboat, using boards as paddles.
Lucien Chopin, 29, was last to leave his house, waiting until his wife and three kids, ages 7, 5 and 1 were safely away.
He was finally joining them late Thursday, hoping they would find a shelter.