Pith helmet

A pith helmet was a headgear used to protect from the sunlight on tropical parts such as Africa and southern Asia.

A pith helmet is seen in the wardrobe when the Tenth Doctor's deciding his outfit. (TV: The Christmas Invasion)

Godascre and his soldiers wear pith helmets. (TV: Empress of Mars)

K9 Mark III wears a pith helmet on Egypt. (COMIC: City of Devils)