GNU Archimedes is a semicondutor device simulator in a quite general context. So when you simulate a new device, you have to specify the lattice temperature. If the user does not specify this value, the room temperature will be taken as default (i.e. $ 300$ Kelvin degrees). All the temperatures are given in Kelvin. So if the user deal with a cryogenic device, i.e. working at $ 77$ Kelvin degrees, he have to specify the following row in the input file
LATTICETEMPERATURE 77