[masraum]

Originally Posted by red-beard

In amateur radio, the power output is much much higher. Handi-talkies can be up to 5 Watts. I remember the biggest concern was a wavelength which matched the optic nerve, about 3-6 cm. Most HT's are 2m/60cm.

I think most of the cell phones these days max-out around 300mW. And most of the time they run far lower output.

As far as "heating" is concerned, the reason microwave ovens use the specific frequencies they do is that they are readily absorbed by water. And 1200 WATTS takes a minute to boil a 8 oz (250ml) of water.

Assuming 10% of a 300mW signal were absorbed, that is 30mW. (I say 10%, because if 100% of the signal were absorbed, the call would drop.) 30mW can hardly cause any heating.

My guess is that the heat is caused more by the contact and maybe the battery warming the phone which then warms the face due to direct contact. I don't think any radio frequency radiation from phones is going to have any measurable affect.