I've often used touching glass windows as a quick way to
check temperature. This device is intended to simulate
that. A combination of a heater (easy) and refrigerator
(harder, but doable), would cause a panel on the device to
feel the same temperature. The device itself would set its
temperature based on a wireless technology, either
from a thermometer placed outside or from a a weather
Technology note: In general, this relies on three pieces of
1) A heater (e.g., a metal coil). This is trivial
2) An air conditioner/refrigerator (doable in a portable
3) The inside of the device will probably have a block of
material with medium heat capacity, high thermal
conductivity, low volume, and high surface area (low
volume and high surface area basically just means a lot of
grooves), with part of thermal material exposed on the
outside of the device.
Note: The thermometer doesn't actually have to a true
match for the actual temperature; materials with higher
thermal conductivity feel warmer/cooler.
This is kind of a weak product, but it's a much more
intuitive way to answer the question, "what temperature is
it outside?" than a thermometer. I could imagine using this
as a physical aid when informing children, "it's cold
outside" or "it's hot outside".