At a children's hospital in Idlib, Syria, it's important to know the three warning lights: flashing yellow means warplanes are nearby, red signals active bombing in the area, and blue alerts staff that casualties are on their way.

Because in Idlib, nowhere is safe.

A province in Syria's northwest, Idlib is the last opposition stronghold against the government of President Bashar al-Assad. Under attack by the Assad regime, it is regularly bombarded by Syrian government and Russian airstrikes. Turkey, the opposition's main backer, is helping defend it on the ground but has no air support.

Over a million people have been displaced from their homes because of the fighting, which has created what rights groups are calling the worst humanitarian crisis of the entire 9-year Syrian conflict.

Trapped in makeshift camps along the Turkish border, many struggle to access even basic aid and endure freezing temperatures with no real shelter.

The doctor who greets us doesn't want to be named or for her hospital's exact location to be revealed because she's afraid it will be bombed.

"They've destroyed many, many hospitals," she says. "But we have to do something for the people here because there is a low number of doctors and nurses working."

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When the war began, as other doctors fled to Europe, she stayed behind. Now, with two young children of her own, she would contemplate leaving if not for the injured children and the premature babies in incubators that she looks after.

"(Expecting) mothers come to the hospital tired and afraid," she says. "Two babies arrived at the hospital dead last week because the camps are so cold, and there is no food."

The three warning lights are also displayed at another hospital, where in the basement, a child is prepped for surgery. It's dark and grimy, but it's safer than above ground, and it's one-and-a-half-year-old Bayan's only hope.

She cries out for her mother as the doctors prepare to take shrapnel out of her leg.

"It was an airstrike," Bayan's mother, Umm Abdo, says. "A missile landed right next to us while we were sitting on the ground. I was cooking for my kids when it happened."

Even at such a young age, Bayan's mother says her daughter understands what is happening around her. As warplanes pound rebel-held positions around the city, she says that most children do.

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At a nearby refugee camp, Umm Mohammed and her four children live in tent 45. Two of the children have special needs.

Umm Mohammed's husband was arrested by the Assad regime three years ago, and she believes he's dead. She and her family fled their home because the hospital next door kept being targeted by airstrikes.

When asked about life in the camp, Umm Mohammed breaks down.

"People here are trying to help," she says, crying. "But I'm still alone with my children."

Other people in the camp say all they want to do is go home, but as the war closes in, that isn't an option. Some say they want to go to Europe where it's safe.

Then they ask the questions that are asked time and time again by Syrians in Idlib: Why isn't the international community doing something to stop the war? Do they not know what is happening here?