To help feed his Pakistani family, ten-year-old Mohammad Adnan leans towards the blazing furnace, moulding bangles for up to 12 hours a day to earn 18 cents.
"I'm just starting and can make six to seven tora (300 bangles) a day and earn 14 to 15 rupees," said Adnan, a smile on his tired face in Pakistan's southern city of Hyderabad.
Adnan is just one of thousands of Pakistani children toiling to manufacture the popular glass bracelets that adorn the arms of practically every woman who can afford them in the south Asian nation of 170 million.
The jewelery is particularly popular on festive occasions such as this week's Eid al-Fitr celebration that marks the end of the Muslim fasting month of Ramadan.
In the build-up to Eid, Pakistani artisans work overtime, hunched for hours over fires to churn out bangles in every possible color, exerting maximum effort for least reward at the bottom of a high-earning industry.
Mohammad Kaleem, Adnan's father, is one of the best paid, earning 3,000 rupees (36 dollars) a month for carving names and designs onto the thin glass.
"I inherited this art from my father and now I am transferring it to my son," Kaleem said.
Pakistan's bangle industry started on the banks of the Indus river in 1947 when a large number of artisans migrated to Hyderabad as British colonialists partitioned the Indian sub-continent, creating two independent nations.
But for every bangle given as a present in wealthy homes this Eid, lies a disturbing tale of child labor, poverty and Dickensian misery.
A 2004 survey commissioned by the International Labour Organisation (ILO) found that 10,000 children aged five to 17, 1,000 of them younger than 10 and 29 percent of them girls, were working in the bangle industry in Hyderabad.
Most of them come from poor homes with illiterate parents, dropping out of school because of poverty.
"I couldn't go to school after fourth grade because the whole family has to work to survive and our jobs coincide with school time," said 14-year-old Mohammad Kamran.
Pakistan's last national child labor survey in 1996 said 3.3 million children were at work. Since then, the overall population has risen by 30 million and charities say the figures are much higher.
"We believe these official figures are unrealistically low," says Pakistan's Society for the Protection of the Rights of the Child.
"With at least 23 million children of school-going age not attending school, the actual number of child laborers must be higher," its website says.
The ILO survey said 86 percent of the children worked full-time and that nearly 58 percent spoke of sickness or injury.
The children suffer from fever, skin disease, cuts, wounds, headaches and backache due to heavy loads.
The study highlighted the risks of working for hours at a time near the furnaces used for moulding and joining, and also from toxic chemicals used in coating and painting.
In a closed room of a Hyderabad slum, Fatima Ali, 35, cuts a cylinder of glass into batches of 300, then starts to smooth the bangles over a flame.
"I work along with my husband, three sons and two daughters (who are aged eight to 15) all day, yet we earn little more than 6,000 rupees (75 dollars) a month, not enough to live a better life," she said.
Fatima said she wore a bangle just once, at her wedding 18 years ago.
"I can't wear it now, because I feel no attraction in its colors and glitter like other women," she said.