Rubbing nose or scratching face or pulling ears,all are normal babies attributes. You can know if it's Congestion,if baby is unable to sleep properly ,has heavy breath, unable to take feed properly. Has runny nose,sneezes more than 5 times a day. Sleeping in a c is not an issue,we slept in AC with newborn,j just see that baby neither is too cold or too hot. Swaddle her properly in cotton sheet. And if required,double swaddle with baby soft blanket. It usually keeps the baby warm. The t4ick is,generally baby needs one extra layer than you. If her hands and feet are damp,she is too hot. Hope you got ur answer!