impervious \im-PUR-vee-uhs\ , adjective) - 1 : Not admitting of entrance or passage through; impenetrable. 2 : Not capable of being harmed or damaged. 3 : Not capable of being affected.
"She lay peacefully asleep, impervious to the man who watched her. Impervious to the fate that awaited her. Impervious to the cold that would blanket her." -- Robin Schone, 'The Lover'
Impervious comes from Latin impervius, from in-, "not" + pervius, with a way through, hence penetrable, from per-, through + via, way.