Wherever gas burns, as in certain cooktops, ovens, and space heaters, it makes a chemical called nitrous oxide. This gas can inflame your lungs, make you cough and wheeze, and trigger asthma. You also make it when you burn wood, oil, coal, or kerosene. Make sure your appliances are installed the right way. Do regular maintenance, and pay special attention to how they send waste gases out of the house.