Between 2009 and 2016, emergency room charges nearly doubled. They’re rising at four times the rate of overall health care spending, according to the Health Care Cost Institute. “CBS This Morning” has partnered with Kaiser Health News and NPR on their “Bill of the Month” series, which uncovers shocking medical bills. This week, we explore the story of one Colorado man who got hit with a huge bill after his bachelor party.

During the evening after his bachelor party, Cameron Fischer was so nauseous from a hangover that his fiancée Katlynn decided they should skip their own rehearsal dinner to go to the emergency room.

“He just couldn’t hold anything down,” Katlynn said. “I wanted to take him to the hospital just to make sure that he was ok and ready for our wedding.” At a freestanding ER outside of Denver, a blood test confirmed that Cameron was dehydrated.”It was 2 liters of saline,” Cameron said. “It took about 30 to 45 minutes to go through it all.”   Cameron said that he felt great on his wedding day — but that his stomach was back in knots a few weeks later when the hospital bill arrived.  The total was more than $12,000, including a $7,644 “facility fee,” $700 for two bags of saline, and charges for tests he said he didn’t even know were ordered. “What they told me was that by signing the consent form whenever I checked in, that authorized them to run any and all tests,” Cameron said.   North Suburban Medical Center said in a statement that “when patients present to our emergency room, board-certified physicians examine and address their medical needs. The amount patients pay out of pocket for their emergency room care is based upon their insurance.”Cameron’s insurance company negotiated the bill down to roughly $4,700, and paid nearly $2,100. He owes the rest.

“My wife and I just recently found out that we’re pregnant,” he said. “So that’s money that would be going to making sure our child is actually cared for.”

According to Dr. Elisabeth Rosenthal, the editor-in-chief of Kaiser Health News, the bags of saline solution that cost Cameron $700 at the emergency room were available at Walmart for $10.99 apiece.

“[At emergency rooms,] the markup is going to be 30, 40, 50 times what would be available on the outside,” Rosenthal added.

Rosenthal noted that patients can cut their costs by turning down blood tests. “You can say, ‘Why, what are they for?'” she suggested. “This young man knew exactly what was wrong.”

She also cautioned potential patients to think “defensively,” and know the hours of local urgent cares so that they can go to those instead.

“Think twice before you use an emergency room,” she added.