that's good that you are cooling things down. The chicks should also have a much cooler area they can go to if they feel too hot. If the chicks have 85 degrees in the warm area, they should probably have at least 20 degrees below that in a cooler space they can go to if they are too hot. When chicks are left with their Moms, they do not always stay under her. Most of the time they are running around, pecking and eating. When they get cold they run to their Mom to get warmed up again. After a couple minutes of warming up they are off, pecking and eating again. My hens have had chicks outside when it's 32 degrees. The chicks spend most of their time pecking and eating, not cuddling under Mom.