Arianna Huffington told Elon Musk to get some more sleep.
But the Tesla CEO snapped back in a 2.30 a.m. tweet.
Musk said he has no choice but to work long hours because the alternative is potentially catastrophic for Tesla.
It follows his brutally honest interview with The New York Times, in which he opened up about his "excruciating" 2018 work schedule.
After another dramatic week for Elon Musk, in which he bared his soul in a brutally honest interview with The New York Times, his acquaintance Arianna Huffington took the time to offer the Tesla CEO some advice.
Musk complained of working 120-hour weeks as part of an "excruciating" 2018 work schedule, which is taking its toll on his physical and mental wellbeing.
Huffington's advice was simple: Get some more sleep. In an open letter on her Thrive Global website, Huffington explained that humans, just like Musk's electric cars, need time to recharge.
"Tesla is revolutionary because it’s all about how we can most efficiently use energy, which holds the potential to change the world," she wrote, adding: "You’re demonstrating a wildly outdated, anti-scientific and horribly inefficient way of using human energy."
Huffington tweeted the post on Friday. And, perhaps in a perfect illustration of her point, Musk responded at 2.30 a.m. on Sunday morning, shortly after clocking off from a shift at the Tesla factory.
"Ford & Tesla are the only 2 American car companies to avoid bankruptcy," he tweeted. "I just got home from the factory. You think this is an option. It is not."
Ford & Tesla are the only 2 American car companies to avoid bankruptcy. I just got home from the factory. You think this is an option. It is not.
— Elon Musk (@elonmusk) August 19, 2018
Dear Elon, please change the way you work to be more in line with the science around how humans are most effective: You need it, Tesla needs it and the world needs it. https://t.co/vy6hdnYKzt
— Arianna Huffington (@ariannahuff) August 17, 2018
Musk told the Times that he often faces a choice of insomnia or taking Ambien, a sedative used as a temporary treatment to sleep problems. His late-night Twitter binges have worried Tesla's board, the Times said.
The company is said to be actively searching for a deputy for Musk to alleviate his workload. Musk said Tesla approached Facebook COO Sheryl Sandberg, but she presumably knocked the company back given she is still at Facebook.
NOW WATCH: What's going on with Elon Musk