>> Unlike microwaves, infrared radiation is natural.
> 
> Both microwave and infrared radiation occur naturally.  It seems to me 
> that cooking is the most "unnatural" thing.  (But that doesn't stop me 
> from cooking.)
> 
> Robert Kesterson
You are right of course.
What I mean is that infrared radiation comes from stuff like bonfires 
and heated stones and the sun. For hunter gatherers there is no way to 
expose their food to microwave in such a dose that it will heat the food.

Floris Fokkinga