Could a wristband replace air conditioning?

Wristify is a thermoelectric bracelet that keeps your body cool or warm.See more pictures of gadgets.

If you've ever used one of those individual seat warmers that come included in a number of cars these days, you probably understand that temperature, and human beings' level of comfort with temperature, is relative. What Volkswagen makers have deemed a "2" on a rising heat scale of 1 to 5 others might simply call "pants on fire." The same level that your friend riding shotgun finds cozy and comfortable might make you grab his ice-cold Mountain Dew and douse yourself below the belt.

The personalized nature of separate seat warmers makes it easy to please everyone, but individual temperature preferences can cause problems in communal settings like hotel rooms, homes and offices. The good news is that a team of techies is working on a new device that allows people to enjoy the individualized comfort of a seat warmer even after they leave the car. This technology is all in the wrist.

Wristify is a prototype device that aims to deliver thermal comfort to users by changing their perception of temperature. Developed by students at the Massachusetts Institute of Technology (MIT), the wearable gadget delivers cooling or heating waveforms, tailored to personal preferences, to a small part of the user's wrist in tiny, quick bursts. The technology is based on the idea that cooling or heating one part of the body can change the wearer's perception of a comfortable temperature. Think about taking a cold shower after a workout or hopping into a heated Jacuzzi on a brisk night, but only exposing a small section of skin and not getting wet [sources: Vanhemert, Burlingame].

Will this new technology mean the death of home heating and cooling and the end of office jockey squabbles over cubicle temperatures? Probably not, but it could make you more comfortable at home and work. It could also cut down on energy bills.