Originally Posted by DIY masochist

They're behind the ear hearing aids. The part that goes into my actual ear canal is just molded plastic, but the electronics are all up behind my ear.

I like the plastic bonnet idea. Maybe I could roll one of those up and keep it in my seat bag...

And on the breathability thing... Even if I commute down into the mid 30s F, I still end up taking the rain jacket off because I'm heating up too much. I usually end up just starting cold in a t shirt, that way I make it to work barely sweaty at all, no matter how hard I ride.