Edit: This post was composed/sent before NoiseFreeGuy's post of 1:31 pm showed up here.
It's funny, though a few have replied to this thread, no one has answered my initial question.
Many have suggested doing tests, but that wasn't what I was asking about.
How would people know the answers to questions without adequate information? (There may be more than one possible answer.)
Why would you believe an answer given without evidence?
If you want an answer that fits your particular situation, and that you can trust, then explore and try to find out more about the phenomenon. (i.e., experiment)
One certainly shouldn't trust something just because one reads it on the internet. For instance the first poster you cite
"Mobile Phone Radiation Health Hazards â€“ How the Speakerphone Could Save Your Life" makes some dubious leaps.
* They ignoring the fact that your brain is encased in a skin/etc. which has a high water content - rather than being exposed unshielded 2cm away from the cell phone antenna.
* They go to great lengths calculating equivalent exposure distance for emitter in a microwave oven, and then just relying on people's fear and uncertainty to say that therefore it is unsafe. (i.e. no evidence is presented that the emissions from a microwave at that distance would be unsafe - relies purely on people's fears))
* If they are that uptight about cell phones, then small wonder they feel things when they are near one. (Worrying about radiation, tensing muscles, paying attention to sensations in that area that don't normally attend to, there are all sorts of ways to make yourself feel things.)
For another view on effects of cell phone radiation and heat - consider
Do Cell Phones Cause Cancer?
by Bernard Leikind
Forget cell phones for cooking brains - how about the real cookers, like exercise.
There are many claims of sensitivity to electrical fields, etc. But so far little to no reliable experimental validation of them (i.e., usually turns out to be psychosomatic, etc.). If one just wants an answer that fits the symptoms, without bothering with experimentation, then psychosomatic is probably your best bet.
Consider also: "Post hoc, ergo propter hoc"
(After which, therefore because of which.)
People assume that because something happens at the same time as something else (or after something else) there must be a causal relation.
People are big on pattern matching - sometimes it is a real pattern, but it is so easy to fool ourselves or to see patterns that don't exist. (Hence the need to experiment, try things out, and do multiple repetitions of experiment.)