How to Run a Computer in a Sub-Zero Environment?

Underdog asks: "I've seen tons of Slashdot articles on cooling hardware, but my company may be taking on the task of wiring a large sub-zero (as low as -14) warehouse with temperature sensors and the requisite network equipment and computers to read them. Our initial proposal includes at least a dozen acquisition computers, hung from the racks in the freezer. Does anyone have any experience with installing computers in extremely low temperature locations?"