The helmets you see helicopter pilots wear are just an upgrade of the ones they wore as kids that the doctors ordered. They were "special"
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Seriously, I wear one. I'd rather not. Especially in hot weather and working on fires etc. However, I can count several fellows whom I know personally whose helmet saved their lives or at least their ability to have a life. When helicopters crash **** literally hits the fan. Rotor blades go through perspex (thats one guy), heads get dragged down and bounced on rocky slopes (thats another guy), transmissions get ripped out and pulled into the cockpit (another guy) and so on... They also come in handy for an extra motorbike helmet for that chick you just met and you don't have a second. Tell her to keep that cord out of the rear wheel!