When Russia invaded Ukraine, civilian doctors swapped their white coats for military fatigues and sacrificed their own safety to treat the waves of casualties coming from the front lines. As the war bled into its second year, video journalists with The New York Times embedded with one group of highly skilled medics at a military field hospital in the Donetsk region where dozens of soldiers were arriving every day with gruesome injuries.

Our video takes viewers to the battlefield where medics perform first-aid surrounded by artillery explosions, and into crowded, fast-paced operating rooms where they race to seal multiple gaping wounds at a time. In a series of intimate interviews, the medics reveal how Russia’s war — and the relentless work of treating the wounded — has taken a toll on their lives.

The medics speak candidly about the physical and emotional fatigue that comes with living in a hostile environment for months. On one quiet morning, a captured Russian soldier arrived with injuries to his shoulder. His presence provoked an emotional response from the medics, even as they upheld their medical oath to “do no harm,” treating him on the same bed as some of the wounded Ukrainian soldiers he’d been fighting.

News of his arrival reverberated throughout the hospital, and some medics stopped to gawk and yell profanities at the enemy in a wheelchair. The P.O.W. was quickly whisked away by Ukrainian special forces and taken into custody.

But there wasn’t time to linger on an enemy Russian soldier. Soon, more troops arrived from the battlefield, with new wounds to treat.

In the same forests where the fighting is taking place, the medics perform triage as artillery explodes all around them, transporting bloodied soldiers in ambulances to the field hospital. The patients are then shuttled on stretchers into crowded operating rooms, where medics seal and wrap their gaping wounds.

While the Ukrainian military has not disclosed how many of its soldiers have been killed or wounded since the invasion began, the relentless flow of patients reflects the staggering cost of 16 months of war on Ukrainian troops. Combat medics have treated about 13,000 soldiers at the field hospital since it opened in October.

For the soldiers, the toll of the war is more than a statistic. Stress and fear are palpable on their faces as they scream out in excruciating pain. For the medics, it’s a grueling cycle of trauma, death and exhaustion.