Because children are often not warned of the dangers they face, they are unaware of the precautions that need to be taken. And, by their very nature, children are ill-suited to long hours of strenuous and monotonous work. The effect of carrying heavy loads or maintaining awkward body positions can be particularly damaging to the skeletal structure of a child worker. In addition, children's level of concentration is lower than that of adults and they suffer the effects of fatigue faster. This is particularly true if they suffer from malnutrition, which is often the case.
Child workers are also more vulnerable to physical and psychological abuse.
In domestic service, beatings, insults, punishment by being deprived of food and sexual abuse are known to be common. Long hours of work not only impair physical and emotional development, they impair learning ability. In developing countries, children work at earlier ages and usually for longer hours. Though data on the relationship between work at an early age and academic performance is rare, the effects are likely to be extremely negative. Roughly half of all secondary school age children were not attending school.