Abstract: A method for reducing nitric oxide emissions from a gaseous fuel combustor includes introducing a combustion gas containing nitrogen and oxygen, such as air, into a combustion chamber and introducing a fuel gas into the same chamber. A cooling gas, such as steam, is interleaved between the combustion gas and the fuel gas substantially at the point where they are introduced into the chamber. The concentration of cooling gas in the flame front is maximized by this method, resulting in a lower temperature for the flame front and, correspondingly, lower production of nitric oxide emissions. Apparatus for carrying out the invention includes a combustion chamber, a body having a channel through which combustion gas can be introduced into the combustion chamber, a fuel gas nozzle for introducing fuel gas into the combustion chamber, and an orifice around the nozzle for interleaving cooling gas between the fuel gas and the combustion gas.