Dawlish,

On Page 576 of University Physics with Modern Physics, Technology Update, Thirteenth Edition (2010), which continues to set the benchmark for clarity and rigor combined with effective teaching and research-based innovation, they write:

"Radiation. Heat transfer by radiation is important in some surprising places. A premature baby in an incubator can be cooled dangerously by radiation if the walls of the incubator happened to be cold, even when the air in the incubator is warm. Some incubators regulate the temperature measuring the baby's skin ..."

Hot objects radiate heat which warms adjacent objects. Cold objects radiate cold which cools adjects objects. The latter is difficult to demonstrate because it is more difficult to maintain a constant cold temperature than a high temperture. The latter is easy using electrical heating. However, holding a thermnometer over an object taken from a freezer will cause the temperature shown to drop.

I hope you will now realise that you are wrong, will apologise and admit your mistake. Cold radiation does exist.

Cheers, Alastair.