America's 250th celebrations in Philadelphia despite extreme heat | Live updates

An Extreme Heat Warning is set to go into effect at noon on Wednesday, July 1 for the entire Philadelphia region.

It is expected to remain in effect until 8 p.m. on Saturday, July 4th.

That includes the city of Philadelphia, counties in suburban Pennsylvania, southern New Jersey and Delaware.

For a full list, visit our alerts page at 6abc.com/Weather.

The National Weather Service says an Extreme Heat Warning is issued when extremely dangerous heat conditions are expected or occurring.

Experts offer the following recommendations:

Avoid outdoor activities, especially during the heat of the day.

If you must be outside, be sure to drink plenty of water and take frequent breaks in the shade.

Stay indoors in an air-conditioned space as much as possible, including overnight.

Check on family, neighbors and pets.

A threatening heat dome will engulf the central and eastern U.S. this week with heat index temperatures - which combine air temperature with humidity - soaring into the triple-digits in some areas. Conditions will bring above-average temperatures to World Cup host cities such as Boston, Philadelphia and Kansas City, Missouri, all of which have open-air stadiums.

The National Weather Service issued an extreme heat watch for Philadelphia and surrounding regions starting Wednesday afternoon and into Saturday evening, with dangerously hot "feels-like" temperatures, another term for the heat index, up to 110 F (43.3 C) during the daytime. As a result, FIFA's Fan Festival in Philadelphia is shifting its hours this week, including Saturday's watch party, which will end at the conclusion of the 1 p.m. game.

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The New York City area could see near-record high temperatures of up to 109 F (42.8 C) with little respite overnight. An extreme heat watch will be in effect from Wednesday afternoon to Saturday evening.

Concerns about extreme heat during the games taking place in the U.S., Canada and Mexico have been mounting for months. In the U.S., heat kills more people every year than all other weather-related events, including hurricanes, flooding and tornadoes, according to the National Oceanic and Atmospheric Administration.

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