Ms. Vázquez said that her son’s condition had improved before the storm, but that the mildew in the air from the lack of air conditioning worsened her son’s breathing. He died on Oct. 4.

Ms. Vázquez, who has since moved to Indiana, also believes her son should be included on the list of storm-related deaths.

“They lied about this and they lied about a lot of things,” said Mr. Malavé, who lost his home in Adjuntas to the storm and then lost his job too. “People should know the real number of deaths. I know there were adults and children who died in that hospital. Who knows what happened there for the three days we were not allowed to visit. How about all those people on oxygen tanks and all that?”

Experts agree that temperature control is critical in hospital settings, particularly for people who are elderly or seriously ill. In South Florida, eight seniors died in a single day when the air conditioning went out at a nursing home after Hurricane Irma knocked out the power. Several more patients died in the days afterward.

The funeral directors interviewed agreed that the majority of people who they have seen die in recent weeks were very old and some were terminally ill.

“If they were teetering on a cliff, this is the thing that pushed them over,” said Olveen Carrasquillo, who is the head of the internal medicine and geriatrics divisions at the University of Miami Miller School of Medicine. “What for me or you is an uncomfortable night — or in Puerto Rico, an uncomfortable three months — can be really bad for the elderly.”