Carlos Rodriguez digs fence post holes on Tuesday in Houston. Meteorologists say scorching temperatures brought on by a heat dome have taxed the Texas power grid and threaten to bring record highs to the state. David J. Phillip/Associated Press

AUSTIN, Texas — On another 100-degree day in Texas, Sean Whitaker lingered outside a Dallas cafe after polishing off an iced coffee, having switched off the power to everything back home except his refrigerator.

“That’s the reason I’m out,” said Whitaker, 52, finding shade at a patio table.

As an unrelenting heat wave grips Texas for a second week, public appeals to stay hydrated and limit outdoor activities have come with another ask of the state’s nearly 30 million residents: Conserve electricity if possible as demand on the power grid is stretched to projected record peaks.

An early summer arrival of blistering temperatures – which have been blamed for at least two deaths – is taxing Texas’ power grid that many residents still view nervously two years after a deadly winter blackout. Regulators warn that Texas may offer a preview of what could be tight demand on grids across the U.S. this summer because of extreme temperatures worsened by climate change.

On Tuesday, the Texas grid was operating under an elevated “weather watch” that does not ask residents to curtail power but raises the possibility. Even some energy experts who have been critical of Texas’ grid management consider outages this summer unlikely, saying winter carries bigger risks.

But as scorching temperatures in some parts of Texas climb above 110 degrees, flirting with records or breaking them outright, air conditioners are cranked and officials are nudging homeowners to be mindful of their electricity usage.

“Please, please do what you can to conserve energy,” said Stuart Reilly, interim general manager of Austin Energy, which serves more than a half-million customers in Texas’ capital.

Forecasters say relief in Texas may not arrive before the Fourth of July holiday. The culprit is a stalled heat dome forged by an unpleasant mix of stationary high pressure, warmer-than-usual air in the Gulf of Mexico and the sun beating overhead, according to John Nielsen-Gammon, the state’s climatologist.

Jairianna Stennis, 10, cools off at the Rosewood splash pad in East Austin on Monday. Mikala Compton/Austin American-Statesman via AP

For some, the conditions have been deadly. Last week, a Florida man and his 14-year-old stepson died after hiking in extreme heat at Big Bend National Park in far West Texas, where temperatures soared to 119 degrees.

In Austin, paramedics have responded to more than 100 heat-related incidents in the past two weeks alone, which city officials say accounts for more than half of all of their heat-related emergency calls since April.

Hot weather has not caused rolling outages in Texas since 2006. But operators of the state’s grid, the Electric Reliability Council of Texas, have entered recent summers not ruling out the possibility as a crush of new residents strains an independent system. Texas mostly relies on natural gas for power, which made up more than 40% of generation last year, according to ERCOT. Wind accounted for about 25%, with solar and nuclear energy also in the mix.

Texas’ grid is not connected to the rest of the country, unlike others in the U.S., meaning there are few options to pull power from elsewhere if there are shortages or failures. In May, regulators warned the public that demand may outpace supply on the hottest days.

“We have the equivalent of the entire city of Oakland, California, moving to Texas every year,” said Peter Lake, who at the time was chairman of the state’s Public Utility Commission but resigned earlier this month.

California has come close to running out of power in recent years, especially in the early evenings when electricity from solar is not as abundant. In Texas, Republicans’ attitudes toward renewables have soured since the 2021 winter blackout, when conservative commentators falsely blamed wind turbines and solar energy as the prime driver of the outages.

Since the blackout, Texas lawmakers say the grid is more reliable and passed bills this year to try to incentivize the development of more “on-demand” generation, which does not include renewables. But even some Republicans continue raising concerns and lawmakers have done little to address demand. Just before the heat wave settled into Texas, Republican Gov. Greg Abbott vetoed a bill designed to strengthen energy efficiency in new construction, saying it wasn’t as important as cutting property taxes.

Doug Lewin, an energy consultant and the president of Stoic Energy, said he worries more about the grid in winter when there is more constant demand to keep homes warm. Any summer outages in Texas, he said, would likely be rotating outages that would last for a couple hours. Still, he said grid operators don’t issue pleas to conserve power lightly.

“I don’t think it’s a cause for alarm,” said Lewin, who also writes a newsletter on Texas energy. “But yeah, it’s a sure sign that things are getting fairly close to the edge.”

Texas isn’t the only state watching supply and demand closely. The annual summer forecast by the North American Electric Reliability Corp., which oversees the nation’s grid reliability, put two-thirds of the continent at risk of shortfalls in the event that temperatures spike above normal.

In Red Oak, just outside Dallas, Mireya Usery does more than just cross her fingers there is enough supply to keep the power flowing: The thermostat at her house gets parked at 78 degrees.

“We don’t want to end up without electricity for too long,” she said, “so we try to do our best.”

Associated Press reporters Jake Bleiberg in Dallas and Kendria LaFleur in Red Oak, Texas, contributed to this report.