The Bir Ayad field hospital is in a single room with no electricity in a former roadside cafe near the front line in Libya's Western mountains.
It's a far cry from the Canadian medical center where Abu Abdullah usually works as the head of the department of cardiology.
Forget about his advanced cardiology training.
Here, the 39-year-old Libyan-Canadian doctor is practicing basic emergency trauma care, using skills he was taught back in medical school.
"I was watching the news and I decided I had to come help," he said. "I'm proud to be Canadian as well as Libyan. I never felt proud to be Libyan before now. We never felt this freedom we feel now."
The field hospital has just three beds, basic medicines and an ambulance parked outside. It was set up after a big battle nearby and with heavy fighting expected on the nearby front line, doctors expect more casualties to come their way soon.
Wounded fighters are brought here from the battlefront up the road to be stabilized before they can be sent up the mountains to the nearest full-service hospital in the town of Zintan.
The wall is spray-painted with a cartoon of Muammar Qadhafi in a trash bin.
This is Abu Abdullah's third trip to Libya. Each time he has managed to get two or three weeks off work by swapping shifts with other staff back in Canada.
When he has to leave here, he will fly home business class and go straight to work the next day.
He asked that his full name not be used and the hospital where he works in Canada not be identified to protect relatives still in Qadhafi-held parts of Libya.
Diaspora Libyans can be found everywhere in rebel-held territory, returning to help out the five-month-old revolt against the Libyan leader.
LIBYANS FROM ABROAD
Colonel Juma Ibrahim, rebel spokesman in the Western Mountains region, said the arrival at the front line of Libyans from abroad, many with middle class professional lives back home in the West, was an inspiration for local fighters.
"They contact me on the internet and Skype from Canada, from England," he said. "They leave behind the comfortable life. Sometimes there is not any place to sleep, there is not any food. And he is coming here, and sometimes he doesn't know anyone."
The field hospital at Bir Ayad was set up a week ago, the brainchild of Abu Ahmed, an orthopedic surgeon who came back to Libya three months ago, leaving his wife and child back in Pittsburgh, Pennsylvania, where she works at a hospital. He also asked that his full name not be used.
He was inspired to return by Gaddafi's brutal crackdown on protests at Zawaniyah, his home town, site of some of the bloodiest repression of demonstrators early in the revolt in March.
Some of his friends and family were captured, some were still in hiding. A brother, also a doctor, hid for four months before finally succeeding in escaping from Libya.
Zawaniyah is now only about 80km (50 miles) away from the front line down the road after a rebel advance last week.
Abu Ahmed, who had been volunteering in the hospital in Zintan, scrounged together supplies to set up this field station to help fighters who, he hopes, will soon advance on his home town.
"We just do first aid. We don't have electricity yet. Most of the drugs, you need a cold temperature. Here it is 40 degrees Celsius (104 Fahrenheit) in the summer," he said.
It's hard being away from his wife. He speaks with her via the internet when he can.
"She's always crying to me, Come back! Come back!'" he said.
Abu Abdullah, the doctor from Canada, is also originally from a village just on the other side of the front. The homecoming has been a joy.
"Today I went to the front line and I met my classmate who I hadn't seen for 20 years," he said. "Amazing."