A digitally based system is designed to sense temperatures at a plurality of places and transmit temperature data along a hard-wire cable or distributed (wireless) network to an integrated data collection and control appliance. The system can perform single "spot" measurements or arrange multiple readings in a database for later use. Semiconductor-based sensors with digital output and data transmission capabilities allow large numbers of sensors to be placed along extended lengths of signal cable consisting of only three or four wires. The device incorporates electrical insulating materials, encapsulants, and mechanical strain relief designed to protect the sensors and transmission lines from failures related to exposure to extreme cold. Though described here for cold region applications, the embodiment of this invention encompasses moderate and tropical environments as well, or temperatures ranging from -40 C to +85 C.