(CNN) — The dangerous, multi-day heat wave is tightening its grip on the eastern United States, shattering records, straining the electric grid and raising the risk for millions of people preparing to celebrate the Fourth of July outdoors. At least 20 locations broke or tied daily temperatu re records Thursday. Multiple East Coast cities were hotter than Phoenix, the southwestern desert city known for breathtaking heat, including New York and Newark. Here’s the latest: • Great American State Fair takes a break: Organizers for the fair, taking place on the National Mall, announced Friday that the event was closing due to extreme heat, with plans to reopen at 5 p.m. The capital hit 100 degrees with a 111-degree heat index at 2 p.m. • Parade canceled: Philadelphia has canceled its Friday Independence Day parade “due to extreme heat,” according to a post from the event organizers. The parade was expected to be one of the nation’s largest this holiday weekend, with participants from every state. • DC’s Capitol Fourth plays on: The public will still be able to attend the US Capitol Fourth concert on Capitol Hill Friday, the US Capitol Police announced. Gates will open at 7 p.m. with a concert start of 8 p.m. Police strongly urged attendees to “bring an ample supply of water to stay hydrated.” • NYC power outages: More than 6,000 customers in the New York metro area are without power as of 2:00 p.m. ET Friday, according to local utility Con Edison’s outage map. The outages are largely due to the ongoing heat wave, Con Edison spokesperson Jamie McShane told CNN. Voltage reductions are also in place in parts of Staten Island, Queens, the Bronx, Brooklyn and Westchester, he said. • Pollution-fueled heat wave: The intensity of the heat and humidity combined this week would have been “virtually impossible” without the effects of fossil fuel pollution, according to an analysis from World Weather Attribution. Washington, DC, Philadelphia, New York City and Boston are all forecast to see highs near or above 100 degrees again Friday. The combination of heat and humidity will make conditions feel even hotter, with heat index values — what the air actually “feels like” to the body — forecast to climb as high as 113 degrees in Washington, 109 in New York City, 111 in Philadelphia and 104 in Boston. The brutal heat continues Saturday for DC, which is forecast to remain near 103 degrees with a heat index up to 110. Philadelphia could reach 101 with a heat index up to 106. New York City is expected to hit 97 and Boston is forecast to top out near 95 degrees Saturday. Human-caused climate change is making this familiar summer weather pattern far more dangerous. The intensity of the heat and humidity combined this week would have been “virtually impossible” without the effects of fossil fuel pollution. The finding was published early Friday from World Weather Attribution, a scientific network which analyzes the role of climate change in driving extreme weather events. Heat is the deadliest weather hazard in the US, and the high humidity increases the risk, keeping temperatures elevated and preventing sweat from evaporating efficiently, making it harder for the body to cool itself. Overnight lows are also hotter now than they were decades ago, making it harder for people to get respite and rest. The risk can build quickly, especially for older adults, children, outdoor workers and people without reliable access to air conditioning. Anyone heading outside for the holiday weekend should plan for frequent breaks indoors or at least in the shade. Drink water often, avoid intense activities and never leave children or pets in parked cars. Heat strains power grid As homes and businesses crank up air conditioning to stay cool, demand for electricity is surging. Energy Secretary Chris Wright directed data centers in the Mid-Atlantic this week to use their backup power supplies instead of using electricity from the public grid, in part to ensure there was enough to power residential air conditioning. Wright’s Tuesday orders were directed at data centers and other large electricity customers served by PJM, the country’s largest electrical grid operator. The PJM region is made up of 13 states. It is home to the world’s largest cluster of data centers in Virginia, and their dramatic energy use has led to serious electricity price spikes in certain Mid-Atlantic states over the past couple years. Outside of the PJM grid, more than 19,000 Con Edison customers in the New York City metro area and stretching upstate lost power Thursday, according to the utility’s outage map. “Heat, humidity, and increased demand for electricity to power air conditioners” are putting additional strain on Con Edison’s system primarily in the Bronx and Queens, the company said in a Friday news release. “Con Edison crews have restored service to more than 60,000 customers affected by scattered outages since the intense heatwave began.” Mayor Zohran Mamdani posted on X to ask residents to set their AC to 78 degrees and unplug appliances to help conserve electricity and reduce the load on the grid. Managing the holiday heat Many cities, including Boston, New York, Philadelphia, Washington, DC, and Raleigh, North Carolina, are opening cooling centers and expanding public resources as the dangerous heat settles in. Washington, DC, has activated an extreme heat alert through July 5 and is expanding cooling centers, hydration stations and emergency medical resources as hundreds of thousands of visitors descend on the nation’s capital for holiday events. Organizers of National Mall celebrations are adding water stations, cooling tents and air-conditioned buses for attendees. New York City opened hundreds of cooling centers and deployed mobile medical vans to provide water, sunscreen and wellness checks. More than 2,200 LinkNYC kiosks are displaying directions to the nearest cooling center. Philadelphia has declared a heat health emergency through Sunday evening. A ceremony featuring a live virtual address from the pope has been moved indoors, and officials have reduced hours for the city’s World Cup fan festival ahead of Saturday’s match between Paraguay and France. Event organizers have also canceled Fourth of July and World Cup block parties. Amtrak has canceled at least 26 trains in the Northeast since July 2, including trains servicing major East Coast cities such as Baltimore, Philadelphia, New York City, and Boston. These cancellations are due to “temperature-related conditions,” Amtrak noted in posts on X. ...read more read less