A heat exchanger includes a first channel with at least one first wall for porting a first fluid and a second channel with at least one second wall for porting a second fluid. The heat exchanger includes a barrier chamber located between the at least one first wall and the at least one second wall such that a rupture of one of the at least one first wall and the at least one second wall does not result in mixing of the first fluid and the second fluid. The heat exchanger includes a support member that extends between the at least one first wall and the at least one second wall.