The fan blows air on the radiator. Those air molecules can’t physically touch the radiator. The electostatic forces of atoms keep everything separated. When you touch something, you are feeling the electrostatic force of your finger’s atoms pushing against the electrostatic force of the object’s atoms.

The electrostatic force (that is the electro magnetic force that electrons radiate) is actually photons. The particle of electromagnetism is the photon. When you touch something you are feeling the photons exchanging between the electrons in the atoms of your fingers and the object.

The definition of radiation is photon emission/absorption.