A safety device for containers pressurized with gas safeguards the gas side of the working chamber of hydraulic accumulators. A relief apparatus (2) reduces an elevated gas pressure in the container (3) caused by heat. The relief apparatus (2) is a component loaded under the influence of a shear force or compressive force. The shape change of the component under the influence of heat on the safety device (1) in a space (5) closed to the outside occurs such that a fluid-conducting connection (6) from the inside of the container (3) to the outside in the direction of the surroundings is enabled.