Occasionally passengers do not heed the advise in the pre-flight briefing, and put their arms up on the combing. With occasionally eye-popping results!
Be sure to keep the canopy closed people! It is completely harmless if it does open - except for perhaps requiring a change of underwear from the extra dose of in flight adrenalin rush.
In summer we regularly fly with canopies open, it is windy, loud, but on a 38°C day very refreshing!
If flying in an open cockpit and staying the right way up is more your thing, then visit Red Baron Joy Flights and fly in an open cockpit biplane along the Great Ocean Road!