For months, Dairon Elisondo Rojas has been an invaluable resource at an immigrant camp in Matamoros, Mexico. The 28-year-old doctor is fighting solo, sans lawyer, to get asylum in the United States after clashing with the Cuban government. In the meantime, he’s working with an international nonprofit called Global Response Management to serve ill people of all ages. The camp is home to at least 2,500 immigrants, and the young doctor has helped folk with everything from asthma to a broken leg.

According to The New York Times, Elisondo is the only full-time doctor in the tent city. Naturally, he has a heavy caseload. “It’s what I know. It’s what I do best,” he told the newspaper.

He and his girlfriend traveled for more than a month to Florida, where they presented their case and got sent to Mexico to await their hearing under President Donald Trump’s Remain in Mexico policy.

Elisondo was allegedly punished for voicing his disapproval of Venezuelan President Nicolás Maduro’s regime while on assignment in the South American country after medical school. Although he was allowed back into his native Cuba, he tells the Times he was harassed by local police and banned from practicing medicine in the Caribbean nation.

Elisondo, whose specialty is critical care, found Global Response Management, an organization that provides aid in high-risk, low-resource areas, by accident, and asked if he could be of service. Elisondo sent his credentials via WhatsApp to Helen Perry, the organization’s executive director, and he now meets with patients in his makeshift office at the camp from 10 a.m. to 4 p.m. local time on a daily basis. The doctor makes $30 a day.

“He doesn’t know this,” Perry said, “but I am going to send him to other places in the world. He is highly trained.”

Elisondo hopes to practice medicine in the U.S. His next court appearance is scheduled for late February.