Within seconds of a flame-up, fire easily spreads. Spattered grease or oil residue on a dirty stovetop will ignite, causing flames to travel across the range. Oil residue on cooking utensils also ignite, and other combustibles like paper towels, paper or cardboard packaging, and dry dish towels nearby will begin to smolder or burn. Smoke—a deadly cocktail of hot gases, including carbon dioxide, carbon monoxide, water vapor, hydrogen sulfide and unburned hydrocarbons (i.e., ash or soot)—rises up off the flames with the heated air.
Extinguishing the fire now is crucial: Do not attempt to move the pot or pan—you risk burning yourself and spreading the fire around the room. And never throw water on a cooking fire; that will just spread the greasy flames. Instead, cover the pan with a lid or cookie sheet to deprive the fire of oxygen and put out the flames.