You need to bring charcoal under this roof to heat the dormitory. You live in this dormitory with a bunch of other kids, and you all have to take turns bringing in the charcoal from outside to heat it.
The dormitory is on an island, so when you go out to get the charcoal you have to take a row (りょう) boat. You row and row and row until you reach the shed with all the charcoal. Then you row and row and row it back to the dormitory.