Months after she suffered heat exhaustion and lost her job in an Amazon.com warehouse in Breinigsville, Rosemarie Fritchman sat in a small conference room pleading for unemployment benefits of about $160 a week.

Opposing her at the hearing before a state referee, who would decide whether Fritchman was eligible for the benefit, was a human resources agent representing her employer.

The testimony of Gwen Golbreski, the human resources representative, was brief and procedural: "She was terminated for attendance," said Golbreski, who attended multiple hearings involving Amazon warehouse workers that day. "We have a no-fault attendance policy."

Fritchman, 67, remained poised and gave a detailed account about how she struggled working in brutal heat until medical personnel examined her and told her to go home. Following company policy, she provided a doctor's note upon returning to work, and she was still terminated without explanation, she said.

"I did the best I could under those working conditions," said Fritchman, speaking more forcefully in her closing remarks. "I didn't want to end up in an ambulance."

This scene has become commonplace since Amazon opened a Lehigh Valley warehouse in 2010. But the human resources agent is not from Amazon. She works for Integrity Staffing Solutions, a company paid by Amazon to recruit workers who unload boxes, process orders and pack shipments for the giant online retailer.

The temporary staffing firm plays a crucial role in Amazon warehouses around the country, especially during the busy Christmas shopping season. Its relationship with Amazon has made Integrity Staffing Solutions the biggest temporary-employment firm in the Lehigh Valley and one of the fastest-growing agencies of its kind in the country.

Part of its role is fighting to keep its workers from collecting unemployment benefits after they have lost a job at Amazon.

Integrity Staffing Solutions is involved in more unemployment compensation appeal hearings — hundreds per year — than almost all other employers in Pennsylvania, according to a state source with access to the confidential records. It even surpasses Walmart, the state's largest private-sector employer that has more than 50,000 workers in Pennsylvania, the source said.

In the first nine months of 2012, Integrity Staffing Solutions was involved in more than 200 unemployment compensation appeals, the source said. No other temporary-staffing firm in Pennsylvania comes close to that number.

The practice reveals one of the ways Amazon keeps costs down and one tactic used by a temporary staffing firm to win Amazon's continued business. Large employers such as Amazon can bid temporary firms against one another, forcing them to look for ways to contain costs, industry experts said.

The pressure to keep costs down means many who take temporary jobs at an Amazon warehouse hoping it will result in long-term stability and independence instead find themselves jobless and fighting for a public benefit that represents their last financial resort.

The Morning Call attended 23 unemployment compensation hearings this year involving temporary Amazon warehouse workers hired by Integrity Staffing Solutions, including hearings for several employees who lost their jobs following illness or injury. Most workers were fighting for benefits of between $100 and $200 a week.

Advocates for the working poor say the company's aggressive stance on unemployment compensation exploits low-wage earners who need the benefit for food, housing and other necessities while they search for other jobs. The workers are often outmatched in the unemployment process.

"It's plain and simple, [companies are] playing the odds," said Maurice Emsellem, policy co-director of the National Employment Law Project. "A lot of people don't show up and a lot of people don't know the law. They're playing the odds because it helps them financially. Does it cost more to have someone show up to the hearings and win a few or does it cost more to have folks collecting benefits?"

Temporary-staffing experts, on the other hand, say the industry faces unique challenges when it comes to unemployment compensation costs that force firms to carefully monitor all claims, not just as a routine business practice but for their own survival. Precisely how many claims Integrity Staffing Solutions defeats is not public. However, defeating even a small fraction of the claims they dispute can save firms a lot of money, experts say.

"Staffing firms are uniquely susceptible to unemployment insurance claims because people come in and come out," said Edward Lenz, senior vice president for legal and public affairs of the American Staffing Association, an Alexandria, Va., trade association. "We can be disproportionately affected by the nature of our business … . We certainly tell firms [monitoring claims] is part of their proper cost management."

The Morning Call sent questions and requested interviews with both Integrity Staffing Solutions and Amazon.

Integrity Staffing Solutions, which goes by the name ISS in the Lehigh Valley, declined to comment.

"Thank you very much for your inquiry," Integrity Staffing Solutions spokeswoman Megan Couch said. "We don't have anything to offer."