Can't Use Helmets in the Sun????

Okay, so I got a nice new helmet for club rides and such. Luckily, so
far, no one's been a Helmet Nazi about it -- just mild chiding
comments, but I just smile and keep pedalling and no one's pulled me
over yet or kicked me out. =)

Thing is, I actually like this helmet. It's so comfortable I not only
wouldn't mind wearing it if I had to, but I almost want to wear it just
for the heck of it! Maybe in winter-time I will, for a bit of head
warmth (which I really don't need, but it's a $100 helmet, after
all...). =D

Anyway, I'm reading the manual -- am I the only guy who likes reading
manuals with his cereal?? -- and I notice in Giro's one-size-fits-all
Owner's Manual that they explictly state *twice* that direct or
indirect heat might damage the helmet.

Could that mean that the summer sun's going to damage the helmet????

Are we supposed to replace our helmets every year or two, even if they
aren't banged up, simply due to, I dunno, UV-induced deterioration of
the styrofoam's molecular structure??? (Materials Science is such an
interesting field...they're building the world's biggest Neutron
Smasher or whatever-it's-called down in TN or somewhere...they hope to
come up with all kinds of exotic materials due to understanding and
then manipulating subatomic physics!)

I still hope no one forces me to wear a helemt...but this Giro Roc Loc
4 is so comfy I would hardly mind wearing one now. Just funny to think
that it might not do any good anyway due to prolonged exposure to
direct sunlight!