Reuters reports demand for electricity in Texas hit a record on Monday.
Residents cranked up their air conditioners to escape a heat wave that is baking much of the U.S. Southeast.
The U.S. National Weather Service has issued heat advisories for much of the Southeast.
In Houston, humid heat will make it feel more like 111-113 F on Monday and Tuesday.
Demand hit 74,163 megawatts on Monday afternoon and could approach 75,000 MW on Tuesday.