You can sculpt shapes out of flame or alter a fire's spread. As a standard action, you can move one 5-foot square of an ongoing fire per kineticist level you possess to any square contiguous to that fire. For instance, a 4th-level kineticist could move 4 contiguous squares from the center of a 20-foot-by-20-foot fire to the fire's edge in order to create a safe path to escape. The fire continues to spread normally after you sculpt it.
You can stop the environment from being on fire so it seems reasonable you can stop a person from being on fire.