Radiant Heat Transmission
Photons through a transparent medium
Unlike Thermal Convection, Radiant Heat Transfer can occur across a vacuum or through any transparent medium like glass or water. Thermal radiation is the transfer of energy in the form of photons that travel in wave form (electromagnetic waves). This electromagnetic radiation, carries energy away from the surface of hot objects like an incandescent lightbulb or the sun. An example of this is warm sunlight felt on your face on a cold but sunny day. This thermal radiation can warm an object even if the surrounding (ambient) temperature is quite cool.
Prevention: A simple solution to thermal radiation is to use a reflective material like aluminum foil (see above). Some foil covered materials reflect 95 to 97% of the radiant heat, allowing only 3 to 5% of the energy through. This dramatically impedes the transfer of thermal radiation and prevents heat buildup. This is similar the the Albedo effect occuring at the earths polar caps.