Amazon.com file photo

Amazon.com says that it spent $2.4 million "urgently installing" industrial air conditioning units in four warehouses, including Amazon’s Breinigsville, Penn., facility that has been at the center of worker complaints and a PR challenge for the e-commerce giant.

Amazon’s statement posted on the company's website is in response to Amazon.com workers complaining about excessive heat inside the Pennsylvania warehouse. The complaints were outlined in a weekend article in The Morning Call of Allentown. The workers described a workplace where the thermometer soars above 100 degrees and where bosses pressure workers to clock in long days. Some workers sought medical attention for heat-related ailments.

The article went viral on the internet and the criticism has been harsh, with some bloggers accusing Amazon of running a "sweatshop," and others questioning whether consumers should shop at Amazon because of the working conditions.

In the company’s statement, Amazon acknowledged the criticism and said employee safety is a top priority:

We welcome and embrace questions about our preparedness and planning, and indeed we routinely ask those internally, but those who know us well don’t doubt our intent or our focus on employee safety.

Amazon said that the situation was made worse by a scorching summer in that part of the country. The company said the air-conditioning units were up and running by late July or early August. Amazon said it was not ordered by any government agency to install. In fact air conditioning remains an unusual practice in warehouses, Amazon said.

The company also responded to complaints that it employes a high number of temporary workers at the warehouse. Amazon said it relies on temporary employees to find good full-time workers and to manage the ebbs and flows in customer demand for retail goods.

Amazon said 1,381 full-time employees work in Breinigsville, all of whom receive full-time benefits including healthcare. Since January, Amazon asid 850 temporary employees in Breinigsville have been moved to full-time positions.