A gas turbine engine includes an engine core having a compressor section, a combustor fluidly connected to the compressor section, and a turbine section fluidly connected to the combustor section. At least one compressor bleed connects a compressor flowpath with a first cooled cooling air path. The first cooled cooling air path includes a supplementary coolant injector connected to a supplementary coolant supply. The cooled cooling air path including a portion exterior to the engine core.