Texas grid operator, ERCOT, asked residents to voluntarily use less electricity on Tuesday as a brutal heatwave in the southern US drives up demand. More than 38 million people across the South and Southwest were under some level of active heat advisory on Tuesday with the extreme heat expected to continue today. In Mississippi, people are still sweltering without power after weekend storms there, with many criticizing Entergy Mississippi for what they see as a lack of preparation.

This is the first time ERCOT has asked residents of the Lone Star State to cut their power usage this year as temperatures soared to 114°F in West Texas (heat indices topped 120°F in the southern part of the state) and power demand set an unofficial June record on Monday. Climate change, mainly caused by the extraction and combustion of fossil fuels, makes heatwaves more frequent and extreme.

The current heatwave comes just days after Texas Gov. Greg Abbott signed a bill to preempt and override any local rules guaranteeing water and shade breaks for construction workers. Republicans say the law merely ensures consistency across the state, but rejected two bills aimed at providing statewide heat protections for outdoor workers including one requiring one 10-minute break every four hours. Federal OSHA regulations do not include standards for protecting workers from extreme heat or assessing worker overexposure. (Heat and grid strain: AP, Texas Tribune, Bloomberg $, Gizmodo, Houston Chronicle; Heat warnings and forecast: CNN; Climate connection: Washington Post $; Workers: Washington Post $; Climate Signals background: Extreme heat and heatwaves)