CHICAGO — The hospital where I work in Aleppo, Syria, is in a basement. The building above has been bombarded so many times that the top floors are too dangerous to use. Barrels and sandbags line the entrance to fortify it as a bunker.

Aleppo is a long way from my home in Chicago. That city, too, has its share of human suffering. Any Chicago surgeon who takes emergency duty can attest to the gun violence that plagues local communities. But the hospital where I work has state-of-the-art resources and some of the best doctors and nurses in the world. Scalpels are sharp, operating rooms are sterile, and specialists are abundant.

Aleppo, too, has some of the best doctors and nurses in the world, but there are so few left. They are exhausted, endangered, and they need help. That is why I volunteer for medical work in Syria; even the few weeks a year that I can offer provide some respite for the handful of surgeons who serve a population of 300,000 in a war zone. It is a heavy responsibility, but I feel I cannot ask world leaders to risk their citizens’ lives to save people there if I myself am unwilling to take such risks.

My weeks in Aleppo are intense. In Chicago, where I specialize in surgical oncology, I see one patient at a time. In Aleppo, I see 20 at once. You live your life one massacre to the next: of children at school, or of families sleeping at home or shopping at a market. We hear the jets screech by, the helicopters whirring in the sky, the mortars launching, then the bombs exploding. Followed by sirens and screaming.