I think its reasonable that as a civilized society we should set age limits as to when a person can work. Granted it may be hard to determine because one might argue that the sooner you teach someone how to do something the better. One might argue also that as a child doing something as simple as spending time helping dad fix the car or mom wash the dishes is now labor and must be regulated. I think we can probably be reasonable about it though and recognize that if you work for or with mom and dad it doesnt have to be considered labor that needs to be regulated by the state. However the physical toll of working a hard job like that on a farm where you are exposed to the elements shouldnt be allowed until you are of an age where you can make better rational choices or just choices in general. As examples you overheat, need to take a break, need to search out water....whatever it is. There is an age when children become better able to do that because they are more aware of themselves. Also I watched a documentary that indicated children are more susceptible to heat stroke and the effects of the sun.