It shouldn't freeze, it only works when the engine is at operating temp, 110 degrees. It's also not likely that it will give a faulty reading, the sensors can go back though, if they do, they will just not work.
91 318is - M50NV (gone)
02 WRB Subaru WRX EJ207 forged, 320 AWHP stock turbo.
85 - 325
02 325i Sedan