Heat wave bakes large swath of US

More than a third of the US population has been advised to stay indoors as a dangerous heat wave is on track to hit millions more people in the days to come.

"Anomalously high temps are expected to persist across most of the country thru this week, with triple-digit temps lingering in parts of the South Central US & a surge of #heat entering the Pacific NW by early next week," warned the National Weather Service in its latest tweet.

More than 100 million Americans were placed under excessive heat warnings as of Tuesday. Altogether, the heat alerts cover 28 states, stretching from California to New Hampshire, the weather service said.

According to the agency's definition, an excessive heat warning is issued when the maximum temperature is expected to reach 105 degrees or higher for at least two days. A heat advisory is put in place when the maximum temperature rises to 100 degrees or higher for two days.

The sweltering temperatures have wilted parts of the Southwest and South Central US for days. Between Tuesday and Wednesday, nearly 40 cities across the region could see high temperatures that shattered previous records, the weather service said.

On Wednesday, the entire state of Oklahoma topped 103 degrees or higher, according to the Oklahoma Mesonet, a joint environmental monitoring project between University of Oklahoma and Oklahoma State University.

"This is the first time in our network's history (dating back to the mid-1990s) to have 120 sites hit that mark on the same day. Before today we had 2 days with all sites hitting 100F or higher (7/9/11 and 7/10/11)," read a tweet from the project.

The brutal heat has led to wildfires, water main breaks, a heightened level of power consumption as well as heat-related emergencies in multiple states.

The extreme heat and lack of rain have caused the ground in Fort Worth, Texas, to shift, resulting in "an usually high number of water main breaks" in the city this summer.

"Through 8 a.m. Monday, Fort Worth Water had 476 main breaks in 2022, with 221 of those in the past 90 days. The telling number is the 182 in the last 30 days — over 38 percent of the yearly total," read a July 18 post on the city's website.

A security camera of a homeowner in Scottsdale, Arizona, captured a UPS driver collapsing on his porch on July 14, a day when the high reached 110 degrees in the city.

Ambulance crews across some of Oklahoma's largest cities are dealing with a surge in heat-related health emergencies, according to The New York Times.

The Emergency Medical Services Authority in Tulsa has responded to 84 heat-related illness calls and taken 55 patients to the hospitals since July 1, when the third heat alert of the year was issued for the city. The agency has responded to 59 calls and taken 42 patients to the hospitals in Oklahoma City since a heat alert on July 7, the Times reported.

In the meantime, first responders are battling more than a dozen active wildfires in Texas as the hot temperatures, winds and dry conditions continue to fuel the fires.

A major heat wave is also building across the northeastern US, according to AccuWeather.

Some 160 million Americans are expected to face temperatures of 100 degrees or higher by Sunday, according to AccuWeather's meteorologists.

Heat advisories already were in place on Wednesday along stretches of the East Coast, from Boston to New York to Philadelphia, where temperatures were expected to hit 90 degrees and higher for several days through at least this weekend, according to the forecast.

Temperatures could nudge toward the 100-degree mark by Sunday in major cities along the I-95 corridor, the forecasters said.