For most of the year, northern Sudan has a sweltering desert climate. But at night during the winter months, temperatures plummet. Winter is hard, and sometimes deadly, especially for the tens of thousands of southern Sudanese and Darfuris displaced by war. This year, winter has come early and will be harsh for those living in shacks on the outskirts of the capital, Khartoum.

 Renda Mohamed is a self-possessed 11-year-old who shares a one room shack with her mom, her dad, her aunt and 10 brothers. Displaced by war, Renda says she is used to living with discomfort in a sprawling slum called Soba Aradi. But there is one thing Renda can't get used to: the cold. And with the onset of winter in Sudan, Renda is worried.

"It gets so cold but we can't do anything," she says. "We don't have anything. It gets so cold. We have two blankets. My mom, my aunt, and the twins use one blanket and the rest of us use another. I cover up with my brothers. We all sleep together, " she adds.

The blankets are just big enough to cover a full-grown adult.

A child stands outside the African Union barbed wire headquarters in Muhajiria town, in Sudan's south Darfur region

Edmund Yakani is a project coordinator with a non-governmental organization in Sudan, the Paguka Development Association. He says aid organizations were unprepared for an early winter, and are now scrambling to find blankets for thousands of displaced families like Renda's.

"We are now in the middle of November," says Edmund Yakani. "Now, the cold season has started. It means December is going to be the worst. If you compare this year and last year's weather, last year the cold season started in mid-December. But this year it started early. It means in December people are going to face a lot of problems, especially IDPs [displaced people]. We are not prepared for this early winter this year."

Mr. Yakani says he is particularly concerned about thousands of families who have been relocated from the outskirts of Khartoum by the Sudanese government in recent months. These families were moved from mud-brick houses, which provide some insulation from the winter cold, to cardboard and plastic shacks in the middle of the desert. Without buildings or trees to buffer the wind, they get extremely cold.

Darfur refugees

During the winter, illness is rampant in the camps. Poor nutrition combined with cold is a breeding ground for tuberculosis and other diseases.

Nine-year-old Salih says he hates to get up for school in the morning. His teacher, Azziza Mohamed, sympathizes. She is worried about the health of her students.

"They don't have proper clothing for this weather", she says. "They come here cold and tired. A lot of them get sick during the winter. They have no clothes and the classrooms are open. Lung infections, colds, coughs, are the biggest problem."

For children who cannot afford a trip to the doctor's office, a lung infection can be a life threatening illness.

The winter is most dangerous for children and the elderly. Clive Tydeman is country director of a Canada-based organization called the Fellowship for African Relief. Mr. Tydeman says 18 deaths were reported last year due to cold winter weather.

"I wouldn't say it's a huge risk to the healthy," he says. "But it's a fairly large percentage of the population which are considered vulnerable. One influences the other. If people are sick, they get cold. If people are cold they get sick. It's a bit of a never ending cycle, as it were."

As night falls in Soba Aradi, the camp darkens quickly. The electric lights of Khartoum cannot be seen from here. The children head home to sleep because there is nothing else to do. Most of them will wake, shivering, in the early hours of the morning.