Refrigidaire refrig that goes warm. Hi Guys... wondering why my fridge goes warm until I remove

Question

Hi Guys... wondering why my fridge goes warm until I remove back wall from freezer and defrost the ice around the cooler mech (no clue what its called but it looks like a silver radiator). it works for a few days then bums out again. Waiting for landlord to replace but running out of patience and cannot afford to loose more food to spoilage. HELP