I have a corn that's my display snake who's kept in a room that usually gets around 74-78. The temps in the room drop overnight too to about 70-72. I have a regulated UTH that's always on to give him a hotspot in case he gets colder and to digest. Corns and Kings are hardy snakes and I haven't had problems with mine. Maybe some more will chime in to see if they're keeping these colubrids in cooler temp ranges too.