 Why does Infield don a lightning rod at the beginning of the story?
The gleaming rod extended above his head about a foot, the wires from it leading down into his collar, along his spine and finally out his pants leg to a short metallic strap that dragged on the floor. The gyro actually passed over a man's shoulder, through his legs, under his arms. Infield stepped into the main stream of human traffic and tried to adjust to the second change in the air. A young man with black glasses and a radar headset (a photophobe) was unable to keep from being pushed against Infield. The magnetic suction dart dropped away from Infield like a thing that had been alive and now was killed.
 He wants to know what it feels like to be a Cured, and therefore he pretends to have a fear of thunder.
 He wants to infiltrate the fraternal club for the Cured in order to prevent Price's authoritarian rule, so he must blend in.  It will protect him against lightning strikes and is meant as a Cure for his astraphobia.  He wants to know what it feels like to be a Cured, and therefore he pretends to have a fear of thunder.  He is tired of working as a psychiatrist at Infield & Morgan and wants to seek out new opportunities in the world of the Cured.