It’s cold here in Chicago. We have a high of 10 degrees today going to -5 tonight. How cold can you fly in? I talked to my instructor who canceled all lessons and rentals for today but the planes are kept in the heated hangar. So what temp can you fly in without causing issues to the engine? Yes I know no one wants to be outside in the cold but if your plane is in a heated hangar and you take it out, start it, do some local practice, come back without stopping the engine elsewhere, is that bad for the engine or perfectly alright?