A transpiration cooled heat sink, a self contained coolant supply and a method of using a transpiration cooled heat sink and a self contained coolant supply is provided and includes a heat sink base structure, the heat sink base structure having a coolant inlet for receiving a coolant and a coolant outlet for distributing a coolant, wherein the heat sink base structure defines at least one coolant channel disposed so as to be communicated with the coolant inlet and the coolant outlet and a coolant distribution structure, wherein the coolant distribution structure defines at least one distribution cavity and includes at least one distribution inlet communicated with the distribution cavity and wherein the coolant distribution structure is disposed relative to the heat sink base structure such that the distribution inlet is communicated with the coolant outlet.