A spiral heat exchanger features: a cold fluid inlet manifold, a hot fluid inlet manifold and at least one spiral fluid pathway. The cold fluid inlet manifold receives cold fluid and provide cold inlet manifold fluid. The hot fluid inlet manifold receives hot fluid and provide hot inlet manifold fluid. The at least one spiral fluid pathway includes cold spiral pathways configured to receive the cold inlet manifold fluid and provide cold spiral fluid pathway fluid, and hot spiral pathways configured to receive the hot inlet manifold fluid and provide hot spiral fluid pathway fluid. The cold spiral pathways and the hot spiral pathways are configured in relation to one another to exchange heat between the cold spiral pathway fluid and the hot spiral pathway fluid so that the hot spiral fluid pathway fluid warms the cold spiral fluid pathway fluid, and vice versa.