To paint the inside of an exterior wall that is stamped concrete, does outside temp have to be 50 or above?

The wall has been painted before, and I'm re-doing it. I'm 1/2 finished, and the temperature outside has dropped below freezing. I keep the house fairly cool - about 65 degrees. I'm trying to figure out when I can resume painting.To paint the inside of an exterior wall that is stamped concrete, does outside temp have to be 50 or above?
I would think surface temperature of the wall would be the deciding factor.