Rad Flush - antifreeze question

I don't know what engine you have, but the Cummins diesels are sensitive to the type of anti freeze needed. Be sure to use exactly what the manufacturer recommends. Temps only slightly below freezing shouldn't matter for overnight sitting time. If worried, throw a trouble light under the hood to keep the chill off until the flush is finished it's cycle and replaced. Don't forget a thermostat change at this time as well. After going through all the trouble to replace hoses, flush and fill, it's something that should be considered. A new radiator cap may be another item you could consider changing now too.