Texas' power grid operator asked residents Tuesday to voluntarily cut back on electricity due to anticipated record demand on the system as a heat wave kept large swaths of the state and southern U.S. in triple-digit temperatures.

On the last day of spring, the sweltering heat felt more like the middle of summer across the South, where patience was growing thin over outages that have persisted since weekend storms and tornadoes caused widespread damage.

In Moss Point, Mississippi, at least 100 structures were damaged by tornadoes over the weekend, according to the state's Emergency Management Agency. No deaths were reported.  

In the Mississippi capital, some residents said Tuesday that they had been without power and air conditioning for almost 100 hours, which is longer than the outages caused by Hurricane Katrina in 2005. Entergy Mississippi, the state's largest electric utility, said its crews had worked 16-hour shifts since Friday, but some officials expressed doubts about its preparedness.

High temperatures in the state were expected to reach 90 degrees on Tuesday.

"The delay in restoring power has caused significant hardship for their customers and it is unacceptable," said Brent Bailey, a member on the Mississippi Public Service Commission, the state's energy regulator.

The request by the Electric Reliability Council of Texas, which serves most of that state's nearly 30 million residents, was its first of the year to cut energy consumption. ERCOT said it was "not experiencing emergency conditions," but it noted that the state set an unofficial June record on Monday for energy demand. The Voluntary Conservation Notice was in effect from 4 to 8 p.m. CT.

In East Texas, storms knocked out power to more than 40,000 people, according to Poweroutage.us. Winona Mayor Rachel Moreno told CBS News her town has been hit "pretty hard."

"For us to be such a small town, I mean, it's made me cry quite a bit," she said.

About an hour away in Marshall, Texas, some residents who lost electricity headed to Immanuel Baptist Church to keep cool. 

In Harrison County, Texas, a West Virginia line mechanic who had been working to help restore power in East Texas died Monday. Judge John D. Oswalt, a Harrison County Justice of the Peace, told CBS News the man "apparently suffered a heat-related incident while working."

CBS affiliate KYTX reported that the 35-year-old mechanic was given medical treatment after telling coworkers he felt ill after working in the heat. He later fell asleep and, when his roommate tried to wake him, he was unresponsive, KYTX reported.

In the oil patch of West Texas, temperatures in San Angelo soared to an all-time high of 114 degrees on Tuesday, according to the National Weather Service.

According to CBS Texas, the heat index in parts of the state could reach 120 degrees Wednesday. 

Many Texans have been skeptical of the state's grid since a deadly 2021 ice storm knocked out power to millions of customers for days. Republican Gov. Greg Abbott has said improvements since then have made the grid more stable, but those improvement efforts continue to draw scrutiny.

In neighboring Oklahoma, more than 100,000 customers were eagerly awaiting the restoration of power and air conditioning following weekend storms that downed trees and snapped hundreds of utility poles. Officials say at least one person in Oklahoma has died because of the prolonged outages, which could last into the weekend for some residents.

In the Tulsa area, residents without power on Tuesday lined up for bags of ice as temperatures reached the mid-90s. Drivers also waited on long lines at gas stations so that they could fill up their generators or keep their cars running for the air conditioning.

Arkansas Gov. Sarah Huckabee Sanders on Tuesday declared a state of emergency because of the weekend's storms, citing damage from the weather and "numerous" downed power lines.

In Louisiana, more than 51,000 electricity customers were still without power Tuesday because of the storms that damaged more than 800 structures around Shreveport alone, according to Mayor Tom Arceneaux. Officials said more than a dozen major transmission lines were still awaiting repairs.

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• Mississippi
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• Heat Wave
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