The Peltier Effect was discovered in 1834 by a French watch maker who lived between (1785-1845). It is also often referred to as thermoelectric cooling. The effect is the propensity to absorb or produce heat on a surface when a current is applied across the junction of two dissimilar conductors. The effect is reversible based on current direction through the junction, so that a Peltier Cooling device can also be used as a heating device.

Peltier effect devices are sometimes used to cool electronic components such as microprocessors, or in other applications consumer-oriented cooling/warming boxes are commercially available for automotive use (keeping drinks cool in a car, or warming a sandwich with the same apparatus).