A photo of a teenager working at a fast-food outlet in the US in a neck brace and arm sling is going viral after a customer told people in a Facebook post why the teenager insisted on working despite his injuries.

Jakeem Tyler, 18, headed back to work just days after a car accident and caught the attention of diner Cameron Nelson , who was impressed by his work ethic as as he worked the cash register of a Chick-fil-A outlet in Indianapolis, according to media reports.

When Nelson asked why he was working when he was clearly injured, Tyler replied that he was working because he needs the money and also to feed the homeless for Christmas.

"We sneeze too hard and decide to call in, but he's working like nothing's wrong," Nelson wrote in a Facebook post that also included a photo of Tyler.

The post has received more than 14,000 shares.

Nelson has since created a GoFundMe page for Tyler.

"I wanted to create this GoFundMe page to help him along in his mission and show some support," Nelson wrote on the GoFundMe website.

Nelson set a goal of US$2,500 (S$2,800). Since then, however, the campaign has raised more then US$12,000.

The money will be used to buy food and supplies for Homeless Hoosiers, a group that helps homeless people find shelters in the area.

Tyler confirmed his goal to the Huffington Post, telling the site: "I was working to use my own money to feed the homeless in the surrounding areas downtown, through various shelters.

Tyler's boss, Chris Tincher, who owns the Chick-fil-A, was not surprised by his employee's big heart, HuffPost said.

"Faith is very important to him," he said, commending the teen's family. "They believe in giving back and serving others and it's really part of his heart."

After Tyler's accident, Tincher said he had been cleared to return to work by his doctors and that the sling and neck brace were mostly cautionary, so he did not further injure himself.

"He enjoys his work and wanted to come back and be with the team," Tincher said. "We're very proud of him."