Like many Texans, Jarrett Milton has been getting ready for the blast of freezing weather expected in the coming days. The owner of two food trucks near downtown Houston, Mr. Milton has coats for his workers and a stock of propane, extra firewood and lots of food.

“You got a storm coming? Oh, let me go buy the place out,” he said. “Because unfortunately, in Texas, you just have to be prepared for the worst.”

Memories of the worst are still fresh in Texas: The punishing winter weather of February 2021 caused a spectacular failure of the electricity grid, leading to the deaths of more than 240 people, some frozen in their own beds.

Since then, officials and lawmakers in Austin have tried to improve the reliability of the grid, making operational changes and passing laws to prevent a similarly devastating failure of critical infrastructure during the cold.