A through-air dryer system that diverts the airflow within the through-air dryer during warm up and cool down from the normal airflow during the drying of paper in the papermaking process. During warm up and cool down, a majority of the airflow is supplied to one of the dryer's heads and extracted through the opposite head to reduce thermal stresses. If needed to further reduce thermal stresses, a minority of the airflow is supplied through the dryer's shell.