Wireless ADSL router - changing signal power ?

[#1]

Water and fat will absorb at 2.4Ghz, and the brain is largely water and fat, but the actual heating effect then depends on how much power is put in. The power is tiny, and simply isn't enough to have any measurable effect.

[#2]

So if you put an egg on your router, the question is - would it explode? 

[#3]

no - but most routers run hot enough to fry an egg!