Tin foil hat to achieve this effect. A belief also exists that aluminum foil is a protective measure against the effects of electromagnetic radiation (EMR) for many unspecified EMR frequencies. Despite some allegations that EMR exposure has negative health consequences, no published experimental scientific evidence has established that tinfoil hats are effective. In 1962, Allan H. Frey discovered that the microwave auditory effect (i.e., the reception of the induced sounds by radio-frequency electromagnetic signals heard as clicks and buzzes) can be blocked by a patch of wire mesh (rather than foil) placed above the temporal lobe. Foil hats have appeared in the films
Tin Woodman iron or steel but coated with tin (in order to prevent rusting) is called a "Tin" object, as a "tin bath", a "tin toy", or a "tin can"; thus, the Tin Woodman might be interpreted (in English, at least) as being made of steel with a tin veneer. One passage in "The Road to Oz," by Baum himself, wherein the Woodman attends Ozma's birthday party accompanied by a Winkie band playing a song called "There's No Plate Like Tin," strongly implies that this is the case. Another explanation may be that the Woodman is "chiefly" made of tin, with iron