The deep freeze is putting gas and power grids to the test.

In the midst of some of the coldest temperatures in years, utility companies in parts of the upper Midwest have asked customers to turn down their thermostats to ensure that there’s enough natural gas to go around.

Ahead of the plunge, grid operators throughout the Midwest had said they were prepared. But this cold snap will be a big test of the resiliency of the energy grid, reports the trade publication E&E News. “The event will be a test of the bulk power system’s resilience, and especially the ability of coal, natural gas and wind generation to deliver power when called upon.”

In Michigan, Consumers Energy — which serves 1.8 million residents — asked customers to set the temperature to 65 degrees or less until noon on Friday. In a Facebook Live video, CEO Patti Poppe pleaded with residents to do their part. The low temperatures created “record-breaking demand” for natural gas. The system worked perfectly, she said, until a fire broke out at a major natural gas compressor station Wednesday morning, making it harder to deliver gas to customers.

Deep Freeze Puts Strain On Midwest Gas And Electricity Grids

Photo: Ryan Garza/Detroit Free Press/TNS via Getty Images