Brrrrr in Chicago
 

So my wife's sister takes the Cayenne for the day, which happened to be the coldest day of the year (also in ten years) and leaves the light on for 4 hours. Once I got it jumped I got the message check coolant temp and also pulled a P3081 code. With the reaserch I did, I could only find info on VW and Audi and they both point to 'Engine Temperature Too Low'. I checked the coolant level and added half a jug but it does seem like radiators are running often, should I replace thermostat?