Final answer:
Christmas lights primarily transfer heat through radiation, specifically infrared radiation, allowing energy to be transferred as heat without direct contact or fluid movement.
Step-by-step explanation:
The heat transfer from Christmas lights is primarily through radiation. This is because the lights emit infrared radiation, which is a form of electromagnetic radiation that can transfer energy in the form of heat without the need for a medium. Unlike conduction, which requires physical contact, or convection, which involves the movement of fluids, radiation can occur through a vacuum or across empty space. Christmas lights are similar to the fire mentioned in the provided reference, where most of the heat to the observers is through infrared radiation. The lights similarly emit visible light and a portion of infrared radiation, which is felt as warmth by the human skin.