The heat from a fire warming your hands is primarily an example of radiation.
Radiation is the transfer of heat in the form of electromagnetic waves, such as infrared radiation, which you can feel as warmth when you are near a fire.
In addition, if you place your hands in the air directly above the fire, the warmer air can transfer heat to your hands through convection, as the warm air rises and cooler air moves in to take its place. So, while radiation is the main mechanism when you feel warmth from a fire at a distance, convection can also play a role if you're in close proximity to the heated air.
Conduction is less relevant in this scenario unless your hands are touching a hot surface, such as a metal pole or a hot piece of wood.