If you talk to any old ham radio operator, they'll tell you about "RF burn" or "RF in the shack," where improperly grounded equipment or being too close to antennas during transmission can cause burns.

Granted, that's at a way higher power output than most consumer devices (a hundred watts or so at a lower frequency versus 100 milliwatts max for phones and most access points).

I don't actually know anyone personally who can prove that they're sensitive to 2.4GHz, but the body is susceptible to RF and microwave radiation at some level.