An apparatus and method for thermal protection is provided. A thermal protection apparatus includes a porous layer attached to an inner structural member requiring thermal protection. The porous layer serves as both a cooling air plenum and a transpiring medium. The porous layer may include a low strength ceramic foam layer. Thermal protection may be achieved by flowing cooling air the length of the porous layer. The voids in the porous layer may be sized to less than 50 .mu.m, producing uniquely efficient thermal protection due to micro-fluidic effects in the air flowing through the layer. A semi-permeable layer may be attached to the outer surface of the porous layer. The semi-permeable layer may prevent erosion of the porous layer and may transform the porous layer into a plenum by making the majority of the cooling air flow the length of the porous layer before exiting through small holes drilled or punched through the semi-permeable layer.