Keep in mind that I might be close enough for near field effects to be relevant.
Anything outside the fence around a transmitter is considered an "uncontrolled area" and there are pretty strict standards for such a place, based on a threshold level well below the place where heating is significant and with some frequency dependent corrections based on how EM energy couples to the human body.
Practically a cell phone up against your head runs up closer to the limits than situations with a broadcast tower, particularly if it is an FM or TV antenna which is way up in the air with a radiation pattern that is null at the ground.
Yes, I do intend to stay outside the fence...
Here's a proof of concept video: https://www.youtube.com/watch?v=FSYj2lEaxhY
And another with a compact fluorescent: https://www.youtube.com/watch?v=lKatgq9sjj8
Presuming the tower is surrounded by a chain link fence, you may need to find a way to get the bulb high enough so that it has line of site to the transmitter.