Whether or not you can shut off or turn down the first two radiators or baseboards in your home to improve heat distribution depends on how the piping is arranged. If all of the baseboards are piped in series (which is usual for single-zone hot water baseboards) then the input of each...
provided a louvered vent into a ceiling (photo at left) to provide warm air to pipes that used to freeze in that ceiling. After that I had no more freeze-up problems in the home. If your bathroom has no heat source of its own, the landlord ought to install one ...