Abdulhamid sells ice cream to passersby at Domiz, Iraq's biggest camp for refugees fleeing violence in Syria, while Sidra reads an Arabic copy of "The Fox and The Crow" in class.

Little but luck appears to have separated the youths' fates -- they both arrived with their families from their war-torn homeland in April.

Sidra now finds herself in a classroom fashioned out of a prefabricated container while Abdulhamid is forced to sell his wares to pay for his father's medication.

The stark difference in outcomes between the two children illustrates a tightening of resources at the camp, which is relatively well-equipped but struggling under the pressure of rapidly increasing numbers of Syrian Kurds crossing the border into Iraq's autonomous Kurdish region in search of safety from Syria's civil war.

Sidra, a nine-year-old with brown hair and a slight frame who sits at the front of her class, is among the luckier ones.

"I love to study," she says, smiling. "I love going to school."

Her classroom is better than many in Iraq. Sidra has to share the prefabricated container with 28 other students and her teacher, but the vast majority of classes are in her native Kurdish and the room is air conditioned.

The classroom protects them from the harsh climate of Domiz, where winters can be brutally cold and summers punishingly hot, with temperatures rising as high as 37 degrees Celsius (99 degrees Fahrenheit).

While Sidra's teacher Ramadan Kusa acknowledges the children have been badly affected by what they went through in Syria, he notes that in Domiz, "the weather conditions are very tough."

"At one point, we had a massive flood -- they have had to go through a lot," the Kurd from Syria's Aleppo city whispers in Arabic.

Nearly 50,000 Syrians have taken refuge at the camp in Domiz, 98 percent of them Kurds.

Overcrowding is pervasive, with the tract of land, allocated by the government of the Iraqi Kurdish region, meant to house just slightly more than half that number of people.

Sidra's primary school, for example, has 1,400 students, and is among three such schools in Domiz, but according to Sidra's principal Ahmed Islam, "we still cannot accommodate all the children in the camp."

In an effort to maximise the number of children attending school, classes have been separated into two batches, with one set going during the morning and a second set in the afternoon.

To make up for all of the time they have lost at school due to the battles between troops loyal to President Bashar al-Assad and opposition groups, children at Sidra's school will also spend the summer in the classroom.

Domiz's crowded schools are only one example of a lack of space at the camp.

Mohammed Hussein, head of the UN refugee agency's office at Domiz, freely admits that the living conditions at the camp are "not ideal", and are likely to get worse before they get better, as some 2,500 refugees arrive every week.

"Since November, the refugees started to suffer from this congestion in the camp because the area that is allocated to them has started to get smaller and smaller," Hussein says.

"We cannot construct more schools, which are really needed, or shelters, and the facilities that come with them, like sanitation units and showers."

Hussein says camp officials are fearful that overcrowding is getting unbearable, and are now "preparing for an outbreak of communicable diseases, especially cholera."

"The risk is very high."

He said that officials "cannot cover 100 percent of refugees' needs. We try to provide the minimum -- food, education, health -- but needs vary from one family to another."

As a result, some families have their children work in order to fulfil those needs.

Among them is Abdulhamid, who jostles between street vendors at the entrance to Domiz selling all manner of goods, from cigarettes to chewing gum, shouting "Mister! Mister!" at would-be clients.

The blond, blue-eyed, boy first says he is 14, before quickly revising that down to 12.

The youth drags along a portable refrigerator he brought from Qamishli, his hometown in northeast Syria, filled with lemon and cherry-flavoured ice cream that he sells for 250 dinars (about 20 US cents) per serving.

"I work from about 8:00 am until sunset," Abdulhamid says, estimating he earns about 10,000 Iraqi dinars (about $9) per day, virtually all of which is put towards buying medication for his ailing father.

While he did not specify the health problems afflicting his father, the boy is matter-of-fact about his circumstances.

"Where I am from, there is war," he says, visibly irritated at being interrupted while working. "Here, if I went to school, I would not be able to earn money."

"I have no choice," he adds. "I have to earn a living."