Heat exchange structures and methods of exchanging heat between fluid flows in heat exchange structures

A heat exchange method, comprising:

• at a heat exchange structure including a primary heat exchange body with a first fluid channel fluidly separated from a second fluid channel by a barrier channel, an inlet manifold in fluid communication with the first fluid channel, and a secondary heat exchange body in fluid communication with the barrier channel that is arranged within the inlet manifold and fluidly couples the barrier channel to an external environment outside the heat exchange structure,
• flowing a hot fluid flow through the first fluid channel;
• receiving a cold fluid flow at the inlet manifold;
• cooling the secondary heat exchange body with the cold fluid flow;
• flowing the cold fluid flow to the second fluid channel;
• and
• communicating heat from the hot fluid flow to the cold fluid flow through the barrier channel.