A cooling system (1), especially for cryopreserving biological samples (2), comprises a cooling chamber (100) delimited by a bottom area (110), side walls (120), and a top area (130), and a cooling device (200) for cooling the cooling chamber (100) using liquid nitrogen (220). At least one of the side walls (120) includes at least one predetermined wall element (125) which is a portion of at least one of the side walls and can be moved relative to the associated side wall (120) in such a way that a wall opening can be formed in said side wall (120). Methods for operating the cooling system (1) in case of an emergency are also described.
