• The Empire State Building is illuminated behind the Con Edison Power Plant in Manhattan, New York City, New York, U.S.

The Empire State Building is illuminated behind the Con Edison Power Plant in Manhattan, New York City, New York, U.S. (Photo : REUTERS/Andrew Kelly)

Utility company Con Edison on Thursday asked its New York City customers to conserve energy as a heat wave grips sections of the United States, potentially straining power grids.

The company has responded to scattered outages since the heat wave began on Wednesday, and has restored power to about 2,300 customers, Con Edison said in a release, adding about 35 of its 3.5 million customers were facing disruptions at present.

Like Us on Facebook

"Con Edison is ready to respond to any service problems that occur due to the heat and humidity hitting the area this week and urges customers to conserve energy," it added.

In Texas, that state's power grid operator also forecast demand would reach its highest this year on Thursday as homes and businesses crank up their air conditioners to combat another heat wave.

The U.S. National Weather Service has issued an excessive heat warning for parts of New York for Thursday.