It was a harsh lesson last night, but this is useful for future reference;
I put my Aero; mint in the refridgerator a day before consumption.
Now, the thing I usually like about my Aero's is that you can savour them, savour the taste by popping each peice slowly into your mouth and 'feeling the bubbles melt'. First comes the sensual feeling of the thin layer of milk chocolate melting down, then comes the filling, setting your mouth alight with mint niceness, mingled with the creamy chocolate taste. =P
So anyway, I take this Aero out of the fridge, the chocolate is as hard as anything (NO MELTING!) and the mint filling turns almost tasteness.
Basically, never put your Aero in a fridge, less' it's melting, or the weather is hot. Spoils it! :p