Many domestic and military aircraft use gold-coated acrylic windows in the cockpit. In cold weather, these windows, carrying an electric current, help eliminate frost that might diminish the vision of the pilots. These thin coatings of gold also help avert fogging as the plane ascends through moisture-laden clouds. During warmer weather, gold's reflectivity helps maintain cool cockpit temperatures on hot runways. In flight at high, cold altitudes, gold's thermal conductivity helps retain the heat of the cabin, keeping the crew warm.
Carbon monoxide is generated by gas-fueled space heaters, smoking and fires.
Another serious pollutant, nitric oxide, is formed in the engines of cars and trucks. When mixed with air, nitric oxide plays a key role in the generation of smog, ozone and other pollutants. Gold, when deposited with metal oxides in monitoring devices, spurs a remarkable increase in the efficiency of converting carbon monoxide to carbon dioxide. Gold particles, when coated over aluminum oxide, promote a 40-percent increase in the conversion of nitric oxide to harmless nitrogen. Field tests for their use in gas masks for firefighters and coal miners, and in carbon monoxide gas sensors also has begun.