In message ,
Alastair writes
All solid objects emit radiation based on their temperature. An ideal
object which emits a Planckian spectrum is called a black body, but the
radiation emitted by non-ideal bodies is often called blackbody
radiation too. The term cavity radiation is also used since, a cavity
produces the thermodynamic equilibrium which is required for true
black-body radiation.

If you place two object at different temperatures side by side with a
gap between them, then the hotter object (with a higher temperature)
will radiate with a greater intensity than the cooler object (with a
lower temperature, since the power they emit is determined by the
Stefan-Boltzmann Law J = sT^4, where s is the Stefan Boltzmann constant
5.67 E-8 W / sq m K^4. The cooler object will warm (i.e. its
temperature will rise) because it is gaining more radiation than it is
losing, and the warmer object will cool because it is emitting more
radiation than it is absorbing. This is an example of the First Law of
Thermodynamics. Eventually both objects will acquire the temperature of
their surroundings, since each of their other five faces will be
exchanging heat with that.

That is all absolutely true. But it ISN'T "cold radiation". Everything
that happens is due to radiation of heat.
--
I'm not paid to implement the recognition of irony.
(Taken, with the author's permission, from a LiveJournal post)