The latest design in tinfoil hats is a formfitting lightweight skullcap that incorporates a retractable sail similar to those sported by sailback dinosaurs and for much the same purpose: both cooling and heating.
A series of quills form a line which runs from front to back, each connected to the next
by a film of thermoconductive material (ie: tinfoil). An artificial muscle (powered by a coin-sized battery and activated by a sensor responding to an ear-twitch), erect the quills which lock into place, spreading the fins to form a "mohawk" sail from brow to nape of the neck. When facing into the wind it provides cooling for an overheated brain; conversely, when broadside to the sun most forms of mental blocks can be melted with surprising ease. Another flick of the ears and the quills drop back down, flush to the head.
The wearer isn't limited to ear-twitches either: the sensor can be adjusted to respond to eyebrow(s) raising, nostril-dilation and of course ambient or head temperature.
Factory Options include (singly or in combination):
Enhanced Heating...
coated with carbon-black for maximal passive heating
The ReCharger...
incorporates a solar-electric film in the fins to recharge your cellphone/PDA/NetTop/Lasers, etc.
Frikkin'Laser Quills(tm)...
come in an assortment of output colours along with a microcontroller for Rock Concert style lightshows.
(In accordance with Federal Laws the provided battery-pack only allows for microjoule output)
Mood Fin...
an enhanced dye coating.
Heavy Duty...
incorporates a bi-directional heatpump at the base of each conductive quill.
XTreme eXams Edition...
our patented heat-pipe quills will get you through the toughest essay assignments.