Impulse sealing apparatus having a forced cooling cycle following the impulse heating cycle, and comprising in combination, a vortex tube which converts a source of compressed gas at ambient temperature into a cold gas stream, a heat exchanger cooled by the cold gas stream generated by the vortex tube, a second source of pressurized ambient temperature gas communicating with the heat exchanger and cooled thereby, and means for removing the second source gas stream from the heat exchanger and communicating with the impulse sealer for supplying chilled gas thereto.