Electricity can be converted from heat thermoelectrically using a peltier generator. This works by an effect which produces electricity at a junction of two different conductors. Up to 0.6W is produced with temperature differences of 60 degrees. This is very useful for flash lights, watches, chargers or other devices requiring little power which can get power from body heat. This can also be used to cool or heat with applied electricity. It is less efficient than other methods, but it is small, mobile, and has no moving parts.