A lance for a burner comprising: an innermost conduit defining a first fluid passage and a plurality of first fuel injection channels, each first fuel injection channel terminating at a first outlet, an intermediate conduit circumferentially surrounding the innermost conduit, the intermediate conduit defining a second fluid passage and a plurality of second fuel injection channels, each second fuel injection channel terminating at a second outlet, an outermost conduit circumferentially surrounding the intermediate conduit, the outermost conduit defining a third fluid passage, a plurality of third air outlets through the outermost conduit and surrounding the first outlets, a plurality of fourth air outlets through the outermost conduit and surrounding the second outlets, characterized in that a plurality of cooling microchannels (200, 200a, 200b, 210, 220, 230, 240, 250) are disposed in areas prone to high temperatures during operation, wherein each cooling microchannel includes and extends between a microchannel inlet (202, 212, 222, 232, 242, 252) in fluid communication with the third fluid passage and a microchannel outlet on an outer surface of the outermost conduit to produce a cooling film along the outer surface, wherein further the innermost conduit, the intermediate conduit, and the outermost conduit have respective conduit inlets (152, 162, 172) co-axial with a longitudinal axis of the lance and wherein the innermost conduit, the intermediate conduit, and the outermost conduit terminate in a tip portion that is perpendicular to the longitudinal axis of the lance, wherein further each of the innermost conduit, the intermediate conduit, and the outermost conduit comprise an upstream arcuate portion fluidly connected to the respective conduit inlet; a vertically oriented portion fluidly connected to the upstream arcuate portion and parallel to the longitudinal axis; and a downstream portion fluidly connected to the vertically oriented portion and transverse to the longitudinal axis and extending inside a downstream portion of the lance, and wherein the downstream portion of the lance has the shape of a prolate spheroid comprising the tip portion, an upper curved surface and a lower curved surface, wherein the upper curved surface and the lower curved surface curve toward one another and are joined at a lance tip. an innermost conduit defining a first fluid passage and a plurality of first fuel injection channels, each first fuel injection channel terminating at a first outlet, an intermediate conduit circumferentially surrounding the innermost conduit, the intermediate conduit defining a second fluid passage and a plurality of second fuel injection channels, each second fuel injection channel terminating at a second outlet, an outermost conduit circumferentially surrounding the intermediate conduit, the outermost conduit defining a third fluid passage, a plurality of third air outlets through the outermost conduit and surrounding the first outlets, a plurality of fourth air outlets through the outermost conduit and surrounding the second outlets, characterized in that a plurality of cooling microchannels (200, 200a, 200b, 210, 220, 230, 240, 250) are disposed in areas prone to high temperatures during operation, wherein each cooling microchannel includes and extends between a microchannel inlet (202, 212, 222, 232, 242, 252) in fluid communication with the third fluid passage and a microchannel outlet on an outer surface of the outermost conduit to produce a cooling film along the outer surface, wherein further the innermost conduit, the intermediate conduit, and the outermost conduit have respective conduit inlets (152, 162, 172) co-axial with a longitudinal axis of the lance and wherein the innermost conduit, the intermediate conduit, and the outermost conduit terminate in a tip portion that is perpendicular to the longitudinal axis of the lance, wherein further each of the innermost conduit, the intermediate conduit, and the outermost conduit comprise an upstream arcuate portion fluidly connected to the respective conduit inlet; a vertically oriented portion fluidly connected to the upstream arcuate portion and parallel to the longitudinal axis; and a downstream portion fluidly connected to the vertically oriented portion and transverse to the longitudinal axis and extending inside a downstream portion of the lance, and wherein the downstream portion of the lance has the shape of a prolate spheroid comprising the tip portion, an upper curved surface and a lower curved surface, wherein the upper curved surface and the lower curved surface curve toward one another and are joined at a lance tip.