Paramedics were summoned to one ASOS warehouse 45 times last year, while a different site attracted 148 ambulance call-outs in the past three years.
Those figures were compiled by the Press Association, and while the reasons behind the emergency responses aren't known, they are believed to relate to workers falling ill or being injured on the job.
Meanwhile, the annual results of both companies show a massive increase in sales translating to tens of millions of dollars.
MP Frank Field told The Mirror: "This sort of thing should have been left behind in the Victorian era." GMB Union regional secretary Neil Derrick said the companies were "making millions", while staff were "literally being taken away in ambulances".
ASOS is a British online fashion and cosmetic retailer popular across the globe.
It launched its Australian site in 2011 and opened an international office in Sydney the following year — but in 2016, an investigation by Buzzfeed made damning allegations of poor working conditions within company warehouses, although ASOS representatives denied the claims reflected the company's wider working conditions.
UK sports-fashion retail company JD Sports is also popular among Aussies, with the first Australian JD Sports store opening in Melbourne in April 2017.
However, those companies aren't the first to make headlines due to allegedly poor conditions.
Earlier this year, an ABC investigation claimed e-commerce giant Amazon applied "abusive supervision" to its local staff.
The ABC investigation centred on eight current and former employees at Amazon's first Australian warehouse at Dandenong South, in Melbourne's outer suburbs, who said the retailer's obsession with quality and pace made them feel "dehumanised".
An Amazon spokesperson denied the allegations in a statement supplied to news.com.au in February.
"The article by the ABC is intentionally sensational in its reporting and is demeaning to the hardworking dedicated people who work at Amazon fulfilment centres and do a great job," the spokesperson said.
"We strive to be a great employer in Australia, and we believe we are making good progress but still have lots more to do."
- News.com.au