From New Babbage Department of Records and Archives
Bone Fever is a deadly illness known in the mining towns of the north, which affects the absorption of nutrients. In children, it attacks the growth plates of bones. Childhood survivors gain deformed features as ear and nose cartilages continue to grow. Survivors appear to gain life-long inoculation from the disease. The cause of bone fever is unknown.
The miners of the northern towns have complicated extended family networks including a formal system allowing for fostering of others' children. Children are often sent away during the digging of new mine shafts due to the belief that trapped gas pockets rising to the surface is the cause of the disease.