Utility companies warned residents in Louisiana it may take weeks before power can be restored to their homes following the devastation caused by Hurricane Ida.
As of Monday morning, over 888,000 customers don't have power, and that number is growing as the storm moves its way into the country.
"It will likely take days to determine the extent of damage to our power grid in metro New Orleans and far longer to restore electrical transmission to the region," Entergy New Orleans, the city's utility, tweeted.
The blackout is coinciding with a forecast that predicts temperatures in the high 80s.
Here are some crucial safety tips for anyone whose home doesn't have power.
The Federal Emergency Management Agency advises people to ensure their portable devices have batteries as close to fully charged as possible.
New Orleans's Office of Homeland Security and Emergency Preparedness recommends communicating via SMS text messaging, because that uses the least amount of cell phone battery power.
If you are using a generator to power appliances or your home, make sure it is positioned outside in a well-ventilated area, as fumes from the generator could result in carbon monoxide poisoning, emergency experts said.
Refrigerators and freezers should be kept closed during the outage.
"The refrigerator will keep food cold for about four hours. A full freezer will keep the temperature for about 48 hours. Use coolers with ice if necessary," FEMA advises.
If it appears at all that a food item is spoiled, emergency management experts say it's best to not take any chances and throw it out.
Affected residents should rely on canned food and other non-perishable food items.
If you need to cook any food, charcoal grills are more efficient for cooking during a power outage. The grills should be used outdoors to prevent any carbon monoxide poisoning.
When it comes to the heat, emergency management experts emphasize constant hydration and wearing thin and comfortable clothes.
The use of battery-powered cooling devices, such as portable fans, is encouraged to beat the heat, according to experts.
If possible, affected users should head to the closest cooling center, such as a library or public pool, to avoid heat stroke or overheating.
FEMA warns that senior citizens are most vulnerable to these conditions during a blackout.