Pith helmet
From Tardis Wiki, the free Doctor Who reference
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)