A system (1) and method for operating a liquid gas evaporator (3), comprising an evaporator (3), a trough (5) carrying the evaporator (3), a housing (7) which surrounds the evaporator (3) on three sides, at least one detector (9) for sensing liquid gas arranged in the trough (5), a line (11) for the distribution of vapor D on the fourth, non-housed side of the evaporator (3) arranged at the margin of the trough (5) which is not closed off by the housing (7), a feed (13), connected to the line (11), and a regulating valve (15) provided on the feed (13) and connected to the detector (9) and at least one shut-off valve (17).