Hurricane Ida knocked power out in parts of New Orleans, many neighborhoods are still without electricity.

It has been almost a week without power in her home. Trying to fall asleep in the heat is torturous, Ms. Crier, 60, said, and she has had to get up and wash herself with cold water in the dark just to get through the night.

As forecasters warned of dangerously high temperatures over the weekend, Ms. Crier was worried about taking care of her mother, who is 81 and returning to her apartment after finding a brief refuge with a friend.

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“It’s a little bit unbearable,” Ms. Crier said as she sat on a folding chair in a gym that the city had converted into an air-conditioned cooling center. “If I could find somewhere to really lay down and stretch out, I might sleep all day and not wake up until the next day.”

National Guard members distributed ice outside a community center in New Orleans on Wednesday.© Johnny Milano for The New York Times National Guard members distributed ice outside a community center in New Orleans on Wednesday.

Nearly a week after Hurricane Ida made landfall in Louisiana, the city of New Orleans is withering in unrelenting heat. Roughly 70 percent of electric customers in the city had no power for a sixth day in a row on Saturday. Many gas stations and convenience stores are shuttered. Neglected piles of garbage are baking in the streets. Amid it all, the sun has continued to beat down, with temperatures exceeding 90 degrees each of the last four days and the heat index hitting 103. The number of visitors at the cooling center that Ms. Crier visited on Saturday nearly quadrupled between Wednesday and Friday.

© Matt Slocum/Associated Press With high temperatures, staying cool has become a priority. Full restoration of electricity to some of the hardest-hit areas could take until the end of the month, the head of a regional electrical utility warned on Saturday.

“We’re definitely seeing more desperation out in the streets,” said Nate Mook, who leads the World Central Kitchen, a disaster relief charity that is giving out 25,000 meals a day in and around New Orleans.

Entergy, the troubled utility company that provides electricity to much of Louisiana, has vowed to restore power to almost all New Orleans residents by Wednesday, which would be 10 days after many people’s lights went out.

But local officials said that each day that passed was making the situation more dire.

“As we get into this point five or six days in, we are starting to see the elderly and vulnerable populations — the heat is starting to have an impact,” said Collin Arnold, the director of New Orleans’s emergency preparedness agency. “It is kind of a race with the clock.”

On Saturday, about 500 people were evacuated to shelters with electricity in Central and Northern Louisiana. A 250-bed federal medical facility opened in New Orleans’s convention center to relieve nearby hospitals, which were too strained by Covid-19 patients to accommodate people struggling from the heat.

Many New Orleans residents have taken to sitting on their porches or stoops all day, dousing themselves with hoses and moving chairs down the street every few hours to follow the shade. When the city turns pitch black each night around 8 p.m., many remain outside for the breeze, with children playing with flashlights on sidewalks as parents fan themselves and wonder aloud with neighbors about when the power will go back on.

Many are in severe need of aid. Ms. Crier said that the store near her home was charging $5 for a bag of ice and that she was worried about how long she would be able to keep food in her cooler. She works as a concessions manager at the Superdome, the stadium where the New Orleans Saints play, but the team has moved its opening game on Sept. 12 to Florida because of the storm.

At the cooling center, Ms. Crier waited to meet with Federal Emergency Management Agency workers about the $500 in relief funds that the agency is paying to some survivors of the storm, but she was told that she was not eligible. She had planned to use the money to leave town and get a hotel — with electricity and air-conditioning — for her and her mother.

With no electricity, the storm has made gas hard to come by, hampering supply chains that provide aid to some of the city’s most vulnerable residents.

John Proctor, the director of food service at the New Orleans Mission, said the charity was spending more than $1,000 each day just on fuel to power generators at its three locations, where it is sheltering more than 300 people. Every day, a team drives into Mississippi to load up tanks of diesel fuel and gas, he said.

“We’re still days away from power,” Mr. Proctor said. “We’re in a dire situation, the entire New Orleans metropolitan area — the lack of power, the smell of garbage.”

Not far away, under U.S. Highway 90 along the edge of the city’s Warehouse District, the roar of motorcycles and cars echoes through a makeshift neighborhood of dozens of tents, mattresses and blankets. Many of those living under the highway were doing so for months before the hurricane, and while they said some things remained the same — there were no air-conditioners or refrigerators to be lost — there have also been stark differences.

The stores and bus stops where people used the bathrooms are now closed, and the city has not cleaned out the portable bathrooms under the highway that are now filled with waste. And in the days after the storm, many of the generous citizens and church workers who regularly dropped off food were unable to reach them.

Pastor Joycelyn Santee, who regularly drops off supplies for the residents here, said she had not been able to return to the area under the bridge for several days after the storm because her house lost power and she had to attend to her own family. But she was determined to return, and she and her team arrived on Saturday with trunks full of toilet paper, bags of ice, toothpaste, deodorant, food and more.

“We do whatever we can,” Ms. Santee said. “This is what we do.”