A platform, housing, conduit, exhaust duct or other structural element that encloses or supports a hot operating engine or other machinery is described wherein a pattern of micro-cavities is defined on the outer surface of the structure for mitigating ignition of a flammable liquid that comes into contact with the structure, the micro-cavities being sized to minimize seepage into the cavities of the liquid because of its surface tension, thereby preventing wetting of the interior of the cavities by the liquid.