Here's why:

* Radiation: Heat transfer by radiation involves the transfer of energy through electromagnetic waves. The campfire's flames emit infrared radiation, which travels through the air and is absorbed by your skin, making you feel warm.

Let's consider why the other types of heat transfer aren't the primary factor here:

* Conduction: This involves heat transfer through direct contact. While some heat might be transferred through conduction if you were close enough to touch the flames, it's not the main way you feel the warmth.

* Convection: This involves heat transfer through the movement of fluids (like air or water). Convection plays a role in how the air near the campfire warms up, but the primary way you feel the heat is through the direct radiation.