Zach Smith keeps cool Friday in Tyler, Texas, at the Fun Forest Pool Sprayground. A cool front brought relief Friday to much of the United States after a heat wave set in earlier this week. For more on the weather, see page 8B.

New York ? Cooler air settled over much of the East on Friday, bringing some relief from a searing heat wave that contributed to more than 200 deaths across the nation since it scorched California last week.

A cool front passed over the New York area late Thursday and headed south. By Friday, temperatures had dropped into the upper 80s, with less humidity. A day earlier, the mercury hit 100 at LaGuardia Airport and 96 in Central Park.

Other cities such as Philadelphia and Washington were expected to cool off soon. Today “they’ll have their break from the heat, too,” said Patrick Maloit, a meteorologist for the National Weather Service.

The air conditioning was turned off at LaGuardia Airport for about five hours Friday as a power-saving measure after utility feeder cables went down. Officials gave bottled water and portable fans to sweaty travelers.

Mayor Michael Bloomberg said energy conservation and careful planning helped the city endure the heat without widespread power outages or deaths. “The bottom line is we didn’t have a big disaster,” he said on his weekly radio show.

Authorities said the heat contributed to at least 50 deaths in the Midwest and East, on top of as many as 164 others in California last week.

In New York, officials confirmed Friday at least 10 deaths were heat-related. In Chicago, at least 17 deaths were blamed on the heat.

On Thursday, temperatures climbed to record levels in several cities, including 97 in Bridgeport, Conn.; 98 in Islip, N.Y.; and 100 in Newark, N.J., and Baltimore. Virginia Beach, Va., reached a high of 99 degrees, but the humidity made it feel like 111.

In Oklahoma, the cool front brought rain to the Panhandle, but the respite was not expected to last. Hot and dry conditions were forecast to return for the weekend, prompting Gov. Brad Henry to institute a statewide burn ban.

The heat wave was part of the same weather system that started temperatures soaring on the West Coast about two weeks ago, said Weather Underground meteorologist Shaun Tanner.