Con Edison crews are working to restore power to 5,000 Bronx residents amid triple-digit temps.
Residents in the northeast and southeast sections of the Bronx are most affected by the outage.
The Con Edison outage map shows about 1,000 customers in Riverdale are without electricity.
Residents there said their power went out at about 11 a.m., forcing families to head to parks, pools and other public spaces to stay cool while crews worked to restore service.
Con Edison said citywide, it has restored power to 31,000 customers affected by scattered outages since the heat wave began.
The utility said heat, humidity and increased demand for electricity have strained the system.
At the same time, the utility reduced voltage by 8% in parts of northern Manhattan and the northwest Bronx, including Riverdale, Marble Hill, Kingsbridge and Van Cortlandt Park. Con Edison said the reduction helps protect the electric grid and maintain service during the extreme heat.
Customers were also asked to conserve energy by limiting air conditioner use when possible and avoiding large appliances, such as washers and dryers.
Across the city, crews continue to work to restore power to 5,000 customers in Staten Island, 5,000 in the Bronx and 6,000 in Queens.