Solar Sombrero- cool head !si si!
 

The T-100 was down for a few weeks and I did my 14-mile commuting by mountain bike in 107-degree F heat index weather.
My Bell helmet has no visor nor shading to speak of.Wearing a French Foreign Legion hat underneath fixed the shade issue but cut off the life preserving head ventilation.
My full-GEEK response,was to fashion a 'sombrero' brim out of double-foil-faced rigid insulation board,aluminum duct-taped to the helmet,and an extended 'shade' made from aluminized mylar/foam windshield sunshade fabric,duct-taped to the back of the foamboard.
I looked like the 'Flying-Nun From Outer-Space' but it was amazing how the UV and infrared got blocked and reflected.A real bacon-saver!
In the future,I may attempt a monostrut supported overhead sunshade which loops over from behind the seat,which would self-destruct in a crash.:p

:D:D:D had a nice laugh with this, but really great idea, at first I thought maybe you just put the sombrero on top of the helmet but I guess it wouldn't fit

http://www.sherv.net/cm/emo/funny/2/mexican.gif

No pictures?

http://casa.colorado.edu/~ajsh/astr1...-large_web.jpg

You mean there really is a place where tinfoil hats make sense?!?!

aerohead -

In the past I've lined the inside of my conical asian hat with double-foil faced bubble-pack insulation that I cut out of windshield sun-screens. Your post makes me want to work on some more versions of this. Version 2.0 will have the bubble-pack on the *outside* of the hat for full-tinfoil anti-fashion fashion.

CarloSW2

From Weird Al's White & Nerdy:
I had to, sorry:)

pic
 

If you really want one I'll see if I can pull that off without destroying the camera!
The thing is vision-warping,super-throw-down hideous!
Years ago,watching a rented Australian movie,there was a scene of a person crossing the sun-parched down-under countryside with a backpack-mounted aluminized Mylar sunshade supported by a couple rods,walking in complete 'shade' at solar noon.
This stuck in my mind over the years,and when my own noggin was getting nuked by UV and infrared my memory sneezed.
I advocate the technology,but if you wear something like it you'll want to keep an eye out for the men in white coats.
I'll get a pic asap.

tinfoil
 

Yes,and I'm semi-living proof!

ouitside
 

Right,my thought was,like the Australian,to intercept and reflect the ultraviolet before it had a chance to convert to the long-wave radiant infrared.
Plenty of quizical looks from passing traffic,but really saved my skull.
Turning 'down' the side edges to allow more shading to the ears is something I'd do in phase-2.The brim wouldn't need all the width I have.
Just a single razor cut,pop the foam,and re-taping would accomplish it.

...you need one of those NASA "cooling" jackets to line your helmet; of course, the attending battery-pack and cooling mechanism might be HEAVY.

...or, you can go for the REDNECK cooler: two ICY-FREEZE headache packs stuffed up into the top of your helmet.