This really shouldn’t came as a huge surprise, but working in an Amazon warehouse can turn you into a prime candidate for the Funny Farm.

A BBC investigation has revealed that conditions inside these behemoth monuments to unfettered capitalism, where workers toil like hamsters on a wheel, could cause “mental and physical illness.”

It seems a leading job stress expert, commissioned by the BBC, employed an undercover reporter. With a hidden camera, the reporter, Adam Little, recorded what took place on his night shifts, which included having to walking up to 11 miles inside a UK-based warehouse, where he was expected to collect orders every 33 seconds.

Little, who surreptitiously got the job as a so-called “picker,” recounted, “We are machines, we are robots. We plug our scanner in, we’re holding it, but we might as well be plugging it into ourselves.

“We don’t think for ourselves, maybe they don’t trust us to think for ourselves as human beings, I don’t know.”

Stress expert Michael Marmot’s conclusion: The working conditions were “all the bad stuff at once.”

He continued: “The characteristics of this type of job, the evidence shows increased risk of mental illness and physical illness. There are always going to be menial jobs, but we can make them better or worse. And it seems to me the demands of efficiency at the cost of individual’s health and well-being – it’s got to be balanced.”

Amazon, reports the BBC, said that official safety inspections had not raised any concerns and that an independent expert appointed by the company advised that the picking job is “similar to jobs in many other industries and does not increase the risk of mental and physical illness,”

Little, the poor little 23-year-old picker, meanwhile, recalled, “I managed to walk or hobble 11 miles, just short of 11 miles last night. I’m absolutely shattered. My feet are the thing that are bothering me the most to be honest.”

The BBC probe comes a month after the news that Amazon would be hiring 70,000 seasonal workers to beef up the staffing at its more than 40 U.S. fulfillment centers.

Amazon described the picking job as “similar to jobs in many other industries and does not increase the risk of mental and physical illness,” and noted that new hires are told some positions can be physically demanding.