A peltier device is a unit that pulls heat from on side to another when under current. Basically it's a disc that when you apply electricity, heat will be transferred through the device, cooling side A and heating side B. If the cooling side A is in contact with a conductive surface (or on the inside of an insulated box), it will pull heat energy from there and expel it on the other side. Typically some sort of heat distribution fins and/or fan would be on the other side to disperse the heat that builds up on side B. They make car adapter plug in coolers that use this technology.
I have no knowledge of what would be needed to automate one of these though.
