From Team Fortress Wiki
- The Area 451 was added to the game.
- [Undocumented] The Area 451 is now tradable, craftable, and able to be used in crafting.
- This hat's name is derived from the urban legend of Area 51, where alien spacecrafts and technology are allegedly held.
- The number 451 is the Fahrenheit temperature at which book-paper catches fire and burns; inspired by Ray Bradbury's novel Fahrenheit 451. The protagonist in this book is a Fireman, who burns illegal books for a living. The number 451 serves as a symbol on the Firemen's helmets.