Abstract: A gas discharge filter is for cooling ionized gases discharged from a circuit breaker. The circuit breaker includes separable contacts electrically connected in series between line and load terminals, a housing, an arc chamber within the housing structured to extinguish an arc between the separable contacts when opened, and an exhaust vent in the housing for discharging ionized gases developed from the arc. The gas discharge filter includes a heat exchanger for reducing the temperature of the discharged ionized gases, and a supporting member to secure the heat exchanger outside the housing and proximate the exhaust vent opening in the exhaust path for the discharged ionized gases. The discharge filter cools the discharged ionized gases as they pass through and around the heat exchanger thus reducing the likelihood of electrical faults associated therewith.