Texas’ grid operator is asking residents to use less electricity between 4 p.m. and 8 p.m. Tuesday as the demand for power soars because high temperatures continue to bake much of the state.

Enough power should be available but an atypical number of power plants that use coal or natural gas have been forced offline, according to the Electric Reliability Council of Texas. Wind turbines are also producing relatively less power compared to past summers.

Forecasters for ERCOT, which manages the power supply for most of the state, expect energy demand could hit 81,230 megawatts at 4 p.m. This would surpass the record for highest energy use – 80,148 megawatts – set last July.

Weather officials issued excessive heat warnings for a large swath of the state, including central and southeast Texas, where the heat index could reach 117 or 118 degrees.