Or rather, linked to completely wrong negative health effects that were just “common knowledge” thus requiring no actual evidence like:

People with light skin should always wear a hat that fully covers the head/face in tropical/equatorial climates (okay, good so far) or else the powerful sun rays will penetrate the skull (?) causing brain damage that will make you go insane (!?!?)

Victorians may have inadvertently protected themselves against excess mortality due to melanomas with their pith helmets, but it’s pretty hard to argue they were actually “correct” with modern hindsight considering the entire chain of reasoning was wrong.

(For example, you see this in Kipling’s writing where he’ll randomly include an ominous case of some guy who forgot/lost his hat and promptly had to be committed to an insane asylum, as one does).