How hot is it?

So hot, amid a record-breaking heatwave, that even talking about the temperature on your thermostat is making people angry. And, apparently, making the Department of Energy website pages disappear.

Last week, New York Mayor Zohran Mamdani advised the city’s residents to conserve energy. To keep the electric grid functioning, he recommended setting home thermostats to 78 degrees Fahrenheit and taking other measures to reduce electricity use. 

He wrote on X that local government was doing the same: “Our City is doing its part too: maintaining the 78 degrees rule in our buildings, dimming/turning off our lights during peak electricity demand, asking private partners to do the same, and powering down non-essential equipment.”

The response, especially among political opponents, has been heated, to say the least. Fox News gleefully highlighted those who “brutally mocked” the mayor, including politicians and influencers who claimed 78 degrees is untenable for vulnerable seniors or that Mamdani may not be following his own advice.

“Show us your thermostat, commie,” the publication quoted from an X post by Spencer Pratt, a TV actor and failed Los Angeles mayoral candidate. 

Complicating matters, and making them even more politically flammable, are reports that the Department of Energy deleted web pages, as many as 6,000 of them, referencing the same type of temperature recommendations and energy-conservation tips.

The Department of Energy did not immediately respond to a request for comment.

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A review of the Internet Archive’s website shows an example of one page available as recently as June that states: “The Department of Energy and Energy Star recommend finding a comfortable indoor temperature during the day and increasing it by 7 degrees F when no one is home. Start with an indoor temperature between 75-78 degrees F during the day.” 

The agency advised homeowners to set thermostats “as high as comfortable” during the summer months and to raise the temperature when no one was home.

That page is no longer on the DOE’s website.

What’s with the current GOP outrage? 

As some news outlets and social media posters were quick to point out, conservative politicians have also called for residents to protect electrical grids by keeping their homes a little warmer in the summer. 

As far back as 1999, then-NYC Mayor Rudolph Giuliani’s office made the same recommendation during that summer’s heat wave, according to an archived press release.

In Texas, where electric grid problems led to 246 deaths in a 2021 winter freeze, the state’s energy council, ERCOT, has since asked citizens to save power by adjusting their thermostats. Before that, even, the state’s longtime governor, Greg Abbott, asked residents to do their part to lower electricity use to avoid grid strain.

“In order to mitigate stress on our state’s electricity grid, Texans should take simple measures to save as much energy as possible,” Abbott said in 2015.

Why set a thermostat to 78 degrees?

Heat waves like the one currently affecting the US can pose major health risks.

But the debate over temperature settings is less about personal safety than about preventing energy grid problems that could lead to blackouts, putting large groups of people and their pets at risk of heat-related ailments and death.

The 78-degree line is what organizations, including Energy Star (and formerly the Department of Energy), have cited for decades as a setting that balances comfort with energy savings. That recommendation dates back to 1979, when President Jimmy Carter mandated the same temperature for public buildings during a major energy shortage. 

There are a variety of technologies and home hacks that can help keep homes cooler in the summer without spiking energy bills, as CNET has reported on.

Read more: Here’s the Right Temperature for Your Thermostat in the Summer